The variation features of GPSretrieved atmospheric Precipitable Water Vapor (PWV) are analyzed, and a comparison is conducted on the radiosonde observations and the retrieved precipitation (PWV) in Yunnan. The results show that PWV can be used to reflect the seasonal characteristics of precipitation, and the values of PWV from lower elevation stations are generally higher than those of higher elevation stations in the same period; the changing trends of PWV and radiosonde observations are basically the same, and the correlation coefficient is approximately 0.89; the variation periods of PWV and precipitation are also identical, with the precipitation starting mostly following the peak after a consecutive increasing of PWV; the large increasing amplitude (or keeping at high level) of PWV can be used as an indicator for forecasting continuous heavy precipitation, but when the peak value of PWV is used as a forecasting indicator, seasonal factors should be considered also.