A method is described for retrieval of several column amounts of atmospheric trace gas from ground\|based mid\|resolution infrared solar spectrum. In the method
a line\|by\|line (LBL) algorithm is used to calculate column atmospheric absorption
the absorption in real atmosphere is obtained by measurement of differential absorption of IR solar spectrum
the column amounts of absorber have been derived by best\|likely method
the feasibility and accuracy are analyzed in the paper in detail. The results show that it has a relatively high accuracy. The method has been applied to monitor the seasonal variation of the column amounts of atmospheric methane and water vapor.