A part of the party members and cadres became corrupt and degenerate since the founding of new China, which had an bad effect on the relationship between cadres and masses. In order to keep political stability of the new China, MAO Zedong used scientific theories according to the actual social condition of China at that time which correctly handled the relationship between cadres and the masses and consolidated the ruling foundation of Communist Party of China. It also safeguarded the rights and interests of the masses. At present, some problems of the relationship between cadres and masses also exist during the social transitional period of China. This study of Mao Zedong’s theories and practices dealing with the relationship between cadres and masses in the founding period of People’s Republic of China is helpful to perfect and develop Chinese socialist theoretical system. It is also conducive to the study of the relationship between cadres and the masses at present.The new China which had experienced the ruins of a war for a long time had to be rebuilt. It needed the support of the people and leadership of the Communist Party of China to restore economy as soon as possible, solve the problems left behind by the old society and stabilize social order. However, people had the senses of distrust and dissatisfaction to the Communist Party of China and they also questioned the ruling ability of the Communist Party of China which influenced the stability of the new country because the overall quality of cadres was low and part of cadres of Communist Party of China had bureaucratic thought and became corrupt after the Communist Party got overall ruling power. Therefore, MAO Zedong combined the Marxist classical writers’ opinions about people with the experiences got in the practices of China’s revolution and construction to deal with the relationship between cadres and the masses in the founding period of People’s Republic of China. On the one hand, he launched a rectification campaign in order to improve the ideological and political level of party members and cadres, cultivate the cadres’ ability to deal with the relationship between cadres and masses. The campaign began from the four aspects of “an impressive display of power ”, “the strength of the disciplines”, “relying on the masses” and “building sound system”. This campaign transformed the party members and cadres’ old though, rectified members of the Communist Party of China, relieved their contradiction with the masses and improved their relationships with the masses. On the other hand, MAO Zedong launched the Movement Against Corruption, Waste and Bureaucracy to solve the corruption problem of the Communist Party of China. During the Movement, he required the leaders to set good examples and take transform and punishment policy for embezzlers. He also widely encouraged the public to participate in the Movement and published “fly” referring to embezzlers of ordinary officials as well as “tiger” the embezzlers of high-level officials.MAO Zedong’s theories for dealing with the relationship between cadres and masses in the founding period of People’s Republic of China are summed up in the long process of China’s revolution and construction. It is the key to lead the victory of the Communist Party of China. The practices of MAO Zedong’s theories for dealing with the relationship between cadres and masses in the founding period of People’s Republic of China improved the relationships between cadres and masses effectively and stabilized the Chinese Communist Party’s ruling status. It provides valuable experience of handling the relationship between cadres and masses for the current China’s government. It also has important practical significance for building the “comprehensive well-off society” and realizing the “Chinese dream” the Chinese nation’s great rejuvenation.