The residual dynamic of tebuconazole and pyraclostrobin in maize straw and soil were measured by liquid chromatography and tandem mass spectrometry (LC–MS/MS). Residues of two chemicals in soil samples extracted with acetonitrile, and maize straw samples extracted with acetonitrile and acetone, were analyzed by LC–MS/MS. The limits of quantification (LOQs) of tebuconazole and pyraclostrobin in maize straw and soil were 0.02 mg/kg and 0.01 mg/kg, respectively. The limits of detection (LODs) in maize straw and soil were 0.005 mg/kg and 0.001 mg/kg, respectively. When the fortified level of tebuconazole and pyraclostrobin ranged from 0.01 to 2.00 mg/kg,the average recoveries of two compounds varied from 83.9% to 113.3% with the relative standard deviation varied from 1.0% to 8.0%. When the maize straw and soil were sprayed with 30% tebuconazole and pyraclostrobin suspension concentrate(SC) at a dosage of 1 050 g/hm2in maize seedling stage,the half-life time of tebuconazole in maize straw and soil were 5.22 d and 14.10 d respectively, and that of pyraclostrobin were 4.78 d and 13.4 d respectively. In conclusion,tebuconazole and pyraclostrobin belong to the easily degradable pesticide types.