The important physic and chemical phenomena， such as air jets， airplane jolts， the ozonopause and so on， closely relate to the position， intensity and fluctuation of the tropopause; therefore， it is extremely important to investigate the tropopause， which is already a focus in recent several decades. The researches on the tropopause are reviewed in aspects of the characteristics of the distribution and variation of the tropopause and the relation between tropopause and ozone， whereby some key problems encountered during researches are summarized and discussed.