In order to evaluate the environment safety and the influence of Fomesafen residue to the succeeding crop, the analysis method of Fomesafen residue in soil has been studied systematically. And a method for determination Fomesafen residue in soil has been developed by extracted with a mixture of methylene chloride and acidified water couple with HPLC-UVD. The results showed that under the optimal conditions, the calibration curves showed good linearity（y=1.3169 x+0.1326, R2=0.9996） from 0.1~10 mg·L-1 concentration of Fomesafen, the recoveries at the three spiked concentration levels range from 78.0% to 114.9%, and the relative standard deviations was less than 8%. The detection limit of Fomesafen was 0.031 mg·L-1 and the lowest concentration detected was 0.06 mg·L^-1 in soil. The results indicated that the method is simple, economic, efficient and sensitive, and it’s suitable for the determination of Fomesafen residues in soil.