Abstract: Sample of fish (2.0 g) was treated by MSPD extraction (with 10 mL of CH3CH), homogenized for 1 min by mixing at a rate of 6 000 r·min-1, and then mixed with 4 g of anhydrous MgSO4 and 1.5 g of NaCl. The mixture was centrifuged for 3 min at a rate of 5 000 r·min-1. One mL of the supernatant was mixed with 50 mg each of N-propyl-ethylene diamine and C18 powder. The mixture was centrifuged for 3 min at a rate of 10 000 r·min-1 and 0.5 mL of supernatant was mixed with 0.5 mL of water and analyzed by HPLC-MS/MS under prescribed conditions. Tests for recovery were made by addition of mixed standard solution at 3 concentration levels to matrixes of 3 kinds of fishes, giving results of recovery in the ranges of 83.7%-93.2% for praziquantel and 85.2%-92.8% for propargite, with values of RSD′s (n=5) ranged from 3.7% to 9.3% and 2.1% to 9.6% respectively. Values of detection limits (3S/N) were found same as 0.3 μg·kg-1.