【Abstract】 Expression of opinion and political communication are two functions of the "letters and visits" system, so "letters and visits" system is not only a resource to maintain the legitimacy of the CCP and the government, but also an important part of power reproduction. Order and stability is necessary for modernization, so to enhance state’s capacity which core is institutionalization becomes an important part of the state-building, an effective institutional basis for political communication and expression of interests as well. Therefore, the "letters and visits" system forms a very complex and complementary balanced relation within the CCP, the government and the people. In practice, the tension and conflict within them is one of the causes of the predicament of the "letters and visits" system, and imbalance relations of the government and the people. So balancing the relations depends on the CCP’ policy and institutional change.This paper use five chapters to study the inherent logic of how the CCP use the "letters and visits" system to build a controlling and moving balance between the government and the people in the unified of the social governance structure, and how the "letters and visits" system lose balance between the two’s relationship in the transformation of social structure.Chapter I analyses the theoretical source of the "letters and visits" system, historical starting point and forming factors in the beginning of the state’s founding. The article put forward that as the guiding spirit of Marxism-Leninism and Mao Zedong Thought of the CCP, the people’s democratic theory which is based on the reflection of the rising and falling of dynasties history is the theoretical root of the "letters and visits" system. As the first socialist country, the Soviet republics created by Lenin, the petition system they created undoubtedly had a guidance role for China’s practice. The "letters and visits" system germing in the revolutionary base areas which was created by the CCP during the new democratic revolution was a manifestation of the ruling party’s mass line. The establishment of new state power, the transformation of the CCP from a revolutionary party into a state-charged party means that the political environment has changed, and the state logic began running in the relationship between the party and people. The spirit of the CCP began to embed into the State framework, making the state has modern spirit, and thus state logic created the need for the establishment of the system. The direct driving force for the establishment of the "letters and visits" system is from the Chinese people who not only had budding sense of modern democracy, but also had profound feeling of the traditional authority.Chapter II analyses the function of the "letters and visits" system and its balancing role in the revolution logic in the unified social managed structure. The people’s expression of interests outbreak intermittently, not only based on the day-to-day politics, but developed a mobilized petition coordinated with the political campaign. In the logic of the revolution, the CCP overcome the drawbacks of the bureaucratic system through the "letters and visits" system, realize monitoring of the government bureaucracy, meet part needs of the people while achieving social control by education and transformation of the people, "letters and visits" system achieved the moving- balance that Communist Party controlled between the government and the people in the political campaign’ intermittent outbreak.Chapter III analyses the "letters and visits" system’ model of governance and performance issues, as well as how it repairs balance dysfunction after the Cultural Revolution. As an anti-bureaucratic mechanism, the petition system has its own bureaucracy, and thus the petition system’ performance of the bureaucratic-proxy mode and elite mode is quite limited. So the petition system mainly relies on mass political movement to promote, not only promoting the institutionalization of the petition system, forming a campaign-style model of governance, but also forming dependence on political movement, the system itself has functions of the political mobilization and error correction of the movement, and thus it achieves a closed reproduction cycle of power. The Cultural Revolution logic led to system’s disorder. Finally the political system balance is restored by vindicating of trumped-up case through the "letters and visits" system to achieve order out of chaos and order, the CCP realize self-correcting through the system, and repair the basis of legitimacy.Chapter IV analyses how political ecology of the social restructuring promoted the "letters and visits" system’s functions to change, and how the market-oriented non-balanced development in the 1990s "created" the "Daobi"(anti-driving) mechanism and trigger the "letters and visits" system crisis. The introduction of market mechanisms made social governance structure diverse under the party and the government-led restructuring. A transitional type of "letters and visits" formed in the 1980s, on the one hand solving the problems left over by history, on the other hand gradually becoming the people’s pipeline of expression of interests. But the non-balanced development formed the major causes of the "Daobi" mechanism in the 1990s, the "letters and visits" system became the main form of the public expression, but the participation "explosion" resulted in the crisis of the system.Chapter V analyses how the CCP strengthened the system to response the Daobi mechanism, and formed strengthening paradox. Daobi mechanism not only caused the crisis but also prompted self-strengthening through system transformation. The local governments formed two operation modes, that is solve-type and control-type. The former is difficult to solve the contradiction between the huge governance objectives and the limited resources, and the latter has inspired the people leapfrog petition and other so-called "deviant" behavior, and as a result system disorder phenomenon is even more serious. The logic of the transformation under path- dependent is to strengthen the "letters and visits" system, and promote the "letters and visits" to manage through institutionalizing and the rule of law, with a view to enhance theeffectiveness of the system------to strengthen communication and build order toprotect their interests. However, "stability" system for the spirit of the "letters and visits" system trapped in a dilemma and formed alienation and anti-back which is between form (the balance of rights and order) and the spirit (that order). The function of social control and order was strengthened; it also exacerbated the tensions between the government and the people, the central and local and led to power involving and social radical phenomenon.Thus, the conclusion reached in this paper, is that "letters and visits" system is an effective mechanism of the CCP party to balance the relationship between the government and the people in the unified community. The petition system formed a campaigning-governance model coordinated to the political movement and with which the balance between the government and the people has been achieved. In the relationship between the government and the people, the ruling party’s policy direction is the key for the "letters and visits" system to balance the relationship between the two leading factors. In the process of the government-leading restructuring of social governance, the "petition" for the interests of the people in the non-balanced development became an important mechanism. However, the emphases of the stability by the ruling party make it is difficult to achieve an effective balance between the government and the people. The solution to the crisis of the system and restoration of the balance between the government and public relations depends on the CCP’ policy and institutional change.At last, this article put forward that the key to alleviate the plight of petition system is "open source". The democratization of the institutions and the building the rule of law, transition of development strategy, as well as the restructuring of the organization are the fundamental sources, and the keys to restore balance of the political system.