A high performance liquid chromatography (HPLC) analysis method for determining thiamethoxam-chlorantraniliprole was established. The conditions of HPLC were ODS2 C18 reversed-phase chromatograph column, the methanol-water as the fluid phase , 230 nm wavelength. The results showed that the starndard deviation of thiamethoxam and chlorantraniliprole were 0.023 and 0.022, the variation coefficient were 0.11% and 0.22%, the average recovery were 99.3% and 98.6% respectively.