Abstract It is argued in this paper that social flow is the marker and mechanism of social transformation and that social flow is in direct proportion to the openness of society and also to social transformation. Proper social flow can lead to such social mechanisms as the suppression of the old to the new, making good omissions and deficiencies, and promoting the good and eliminating the bad. It is also argued that the development of social economy, political system and technology in the process of transformation will directly affect and control social flow. This paper also discusses China's social transformation and social flow towards the end of this century based on China's social realities, pointing out that China's 'flow craze' and 'flow wave' show that the country is moving towards a more open and modern period but a serious imbalance has been caused in different trades, regions and organizations and the flow of the three basic classes, i.e. farmers, workers and cadres, is closely related to their interests and the whole reform.