Abstract: Some researchers think that the shortage of migrate workers in recent years means the end of demographic dividend and the coming of China′s Lewis turning point.This paper attempts to analyze the problem of “migrate worker shortage” from a sociological perspective，and concludes that as China is now at its economic transition stage，abstract economic models are not enough to explain the reasons for this phenomenon.The argument about “limited surplus” of labor force does not correspond to the actual situation in China.The author thinks that the present shortage of labor force is associated with policy changes and reconstructions of family economic structure，and is of a temporary，seasonal and mobile characteristic.Unable to quickly promote industrial structure，cities have difficulties supporting a larger population and thus migrate workers don′t have the opportunity to realize reproduction of labor with grace.Therefore，transfer of surplus labor gradually goes on a decrease and the shortage of migrate workers is just a temporary phenomenon.

Key words: economic transition, shortage of migrate workers, industrial structure, urban and rural dual economic structure, division of labor between generations