An analytical method for an insecticide Fipronil and its metabolite MB 46513 remaining in agricaitunil products has been established which uses GC-ECD and GC/MS for their determination and continuation, respectively. In this method, target compounds are extracted with acetone from agricultural products, concentated, and finally re-extracted with n-hexane. When the sample contains lipid in large quantity, it is first delipidated by partition with acetonitrile, cleaned up with Florisil column, and finally determined by GC-ECD. In the case of vegetables and fruits, which contain lipids in small quantity, the sample is cleaned up with a Florisil column and determined by GOECD. The detection limit of this method is 0.001 micro g/g for both of these kind of samples, the recovery of Fipronil is over 85%, and the C. V. of the recovery is less than 7%. For MB-46513. the recovery is over 63% and its C. V. is less than 9%. This method was applied to 17kinds of agricultural products and no Fipronil and MB46513 were detected.