Abstract: Abstract: 【OBJECT】Comparison between parameters in Dimethoates detection tests by using HPLC and GC was conducted, in order to supply reference for selection of Dimethoates detection method. 【METHOD】 The detection conditions of Dimethoates by using HPLC and GC were optimized respectively, and then the sensitivity, linear relevancy, stability and adding recovery rate of these two method were compared. 【RESULTS】Comparing with the lowest detection limit of 0.1mg/L for Dimethoates by GC, higher sensitivity of HPLC with 0.01mg/L was recorded. Also, HPLC had better linear relevancy than GC. When the concentration of Dimethoates lower than 1.0mg/L, better stability was found by HPLC than GC; but the similar stabilities were observed while the concentration higher than 0.1mg/L. 【CONCLUSION】HPLC was better than GC as the macro- and micro-detections for Dimethoates, which could achieve the requirement of Pesticide Register Residue Test Rule in China.