Cheng Feng (整风运动), or more commonly known as the "Rectification", was a program initiated by Mao Zedong in 1942.

The purpose of the program was to give a basic grounding in Marxist theory, and Leninist principles of party organization, to the thousands of new members who had joined the Chinese Communist Party during it's expansion since 1937. A second, equally important aspect of the movement was the elimination of what Mao called "foreign dogmatism" - essentially, blind imitation of Soviet experience and obedience to Soviet directives.

The movement aimed to and succeeded in reducing the influence of Mao's opponents within the Communist Party led by Wang Ming.

In a speech to Party members in Yan'an on February 1942, Mao said that such dogmatists must be told: " 'Your dogma is of no use,' or to use an impolite phrase, 'Your dogma is less useful than excrement.' We see that dog excrement can fertiilize the fields, and man's can feed the dog. And Dogmas? They can't fertilize the fields, nor can they feed a dog. Of what use are they?"