Abstract: The tropopause has a strong correlation with latitude, and have the periodic changes with the seasons at the same time. The COSMIC radio occultation data from 2008 to 2010 are used to obtain tropopause height at worldwide occultation events by the method of robust covariance estimation. With time and latitude as independent variables, eventually established a tropopause global experience model. The influence of tropopause on wet delay is discussed based on the data of 28 sounding stations distributed globally and based on the Hopfield wet delay model related to tropopause. The results show that the established empirical model of tropospheric top is helpful to improve the calculation precision of wet delay, about 0～15 mm.