In this paper,by detecting the rate of Radon's retention,atmosphere temperature,moisture and pressure,the rate of γ and the moisture content of soil in Uranium tailings of Hengyang City,the grey relational analysis method is applied to analyze and calculate the correlation between Radon's retention and other factors. It is found that,in the resolution factor of 0. 5,the correlation degrees of air temperature,air humidity,air pressure,γ dose rate and soil moisture with radon exhalation rate are 0. 550 1,0. 476 1,0. 631 5,0. 748 2 and 0. 485 ...