19 19 the may 4th movement divided the old democratic revolution and the new democratic revolution, and China society entered the new democratic revolution period.

1949 the establishment of the new China opened a new chapter in the history of China and ended the semi-colonial and semi-feudal society in China since modern times.

With the convening of the Third Plenary Session of the Eleventh Central Committee from 65438 to 0979, China began a new period of reform and opening up.

These three time points are the basis for dividing the important periods of China's modern history.