In its documents the Chinese Communist Party has always stated clearly that the working class is the leading class in China's new-democratic revolution and socialist revolution. The formulation that semi-working class was also a leading class only appeared in a few documents issued around the time of then founding of the People's Republic. Mao Zedong used this formulation when revising the ``Regulations of the Central Committee of the Chinese Communist Party Concerning Differentiation of Classes in Agrarian Reform and Their Treatment'' in February 1948, stating, ``The proletariat and the semi-proletariat (poor peasants) are the leading classes in the people's democratic revolution and in the new-democratic state power, the proletariat being the main leading class.'' When discussing requirements for Party on Organizational Work held on March 28, 1951, Liu Shaoqi said, ``The urban working class and the rural semi-working class, through the Communist Party and under its leadership, staged the revolution, overthrowing Chiang Kai-shek and completing agrarian reform.'' When the report was officially issued on May 5 of that year, the section on requirements for Party membership was deleted and so was the foregoing quotation. However, in the ``Resolution on Consolidating Primary Party Organizations'', drafted in accordance with the report mentioned above, the formulation that ``th Chinese revolution was led by the urban working class and the rural semi-working class'' was retained. In ``Explanation by the Central Committee of the Chinese Communist Party Concerning the Leading Role of the Working Class and the Semi-working Class'', issued in July 1951, that sentence was changed into ``the Chinese revolution was led by the urban and rural working class and semi-working class''. Later on, Yin Yigang and Luo Yunlu, who worked in the Party school attached to Hebei Provincial Party Committee, wrote a letter to the Central Committee and Mao Zedong expressing their disagreement with the formulation that the semi-working was also a leading class. After consulting with Liu Shaoqi and An Ziwen, Mao Zedong agreed to change this formulation. In December 1951, the Central Committee officially issued the ``Directive on Revising the Formulation of the Leading Classes in the Chinese Revolution'', pointing out, ``Whether speaking of the past or the future, we should say only that the Chinese revolution was led by the wording class (through its vanguard the Chinese Communist Party) and the semi-working class should no longer be included as a leading class.''