[Aims]A method for analyzing imidaclothiz·diazinon 5% GR by HPLC was developed,in order to investigate the analysis feasibility of the two active ingredients with one column under the same HPLC condition.[Methods]Using ZORBAX XDB-C18 column and UV detector at a wavelength of 254 nm,with acetonitrile-water as the mobile phase,imidaclothiz and diazinon in imidaclothiz diazinon 5% GR were separated and quantitatively analyzed.[Results]The results showed that the linear correlation coefficients of imidaclothiz and diazinon were 0.9997 and 0.9998,the coefficient of variation were 0.28% and 0.11% ,and the average recoveries were 99.94% and 99.66% .[Conclusions]This method can simultaneously determine the two active ingredients in the sample,with simple operations,high precision and accuracy,and a good linear relationship.