May 1, 1920 (March 13) Gengshen, China for the first time to commemorate the "51" International Day.

1920, the masses of the workers of the industrial cities of Beijing, Shanghai, Guangzhou, Jiujiang, Tangshan mighty towards the downtown, held massive demonstrations, rallies. Li Dazhao specifically on the "New Youth" "" 51 "sports history", introduced the "51" section of the origins of the U.S., other countries workers commemorate May Day activities, calling on Chinese workers this year "51" as the date of the awakening. Chen Duxiu also celebrate this festival on the problems of women workers in the Ministry of Health Spinners Hunan, Shanghai, exposing the truth of the residual value of the capitalist exploitation of workers. Chen made in Shanghai Shipping promptuary workers Federation of laboring consciousness "speech, to clarify the labor to create the world. "The workmanship of the most useful and the most precious" point of view. In Beijing, some young people go out publicity and dissemination of the May 1 Labour Declaration, to arouse the workers for the struggle against exploitation and fight for their rights. Activities to commemorate the "51" International Day for the first time, the history of China's first "May Day" May Day.