The correlations between synchronized air temperature (Ta) and soil temperature (Ts) at automatic weather stations and the land surface temperature (TLS) retrieved from MODIS are analyzed. The results show that for inhomogeneous land surface the correlation coefficients between TLS) and Ta and Ts are unstable, and the correlation coefficients at different satellite passing through time have a great difference. But there is a stable linear correlation between (Ts-TLS)) and (Ts-Ta), and the correlation coefficients at different satellite passing through time are greater than 0.8. A regression equation of soil temperature depending on TLS) and Tais obtained and its standard error is 4.85 ℃.