In order to determine the effective components of 10% fosthiazate granule, the Shimadzu CLC-ODS colunmn（150 mm×6.0 mm，5 μm ) was selected,column temperature was 30 ℃, methanol water（65∶35） was selected as the mobile phase,the flow rate was 1.0 mL/min  and the detection wavelength was 320 nm,the retention time of fosthiazate was 7.0 min.The results showed that  linear relationship was good（r = 0.999 9, n = 5） in the range of 0.053 5～0.855 8 mg/mL, the average recovery rate was 99.12%~99.96% and the RSD was 0.23%. This method was specific,reproducible and accurate to determine the effective components of 10% fosthiazate granule.