RP-HPLC was adopted for the separation and determination of acetochlor and clomazone on the BDS Hypersil C18 column (5μm, 250mm×4.6mm), acetonitrile-water (volume ratio 60:40) as the mobile phase, and the UV detector with wavelength 210nm. The results show that the retention times of acetochlor and clomazone are 9.065min and 5.598min respectively，and the linear correlation coefficients for both acetochlor and clomazone are 0.9998, the relative standard deviations are 1.25% and 1.60% respectively, the average recovery rates are 99.14% and 98.15%. This method is simple, accurate and highly selective.