Abstract: An analytical method was developed for determination of 36 pesticide residues（666、quintozene and its residual metabolites）in oyster mushroom by gas chromatography-tandem mass spectrometry method .This method overcame demand for breaking and instant freezing by QuEChERS method，and more efficient and economical than solid phase extraction.The method were extracted with acetonitrile，further clean-up with N-Propylethylenediamine，determined in modes of electrospray ionization and multiple reaction monitoring，quantified by matrix standard solution external standard method.Results showed that relative standard deviations of 36 pesticide residues content was 2.47%～5.04% under this method for determination.The limits of quantification were 0.000 3～0.010 0 mg/kg，and limits of detection were 0.000 09～0.004 00 mg/kg.36 pesticides had a good linearity was obtained from range 0.05～2.00 mg/L and the r values were greater than 0.990.According to uncertainty evaluation method，items constituting measurement uncertainty involved standard dilution solution，weighing of sample，final volume of sample，and measurement repeatability of equipment were evaluated.Results showed that measurement uncertainty was mainly due to standard solution.