A method was developed for the quantitative determination of amitraz and its metabolites in pond-water by solid phase extraction and liquid chromatography-tandem mass spectrometry .The extraction and separation efficiencies of analytes were investigated using different organic solvents and SPE columns.In the optimal conditions,the calibration curves were linear in the range of 20-2 000 ng/L.The limits of detection for amitraz and its metabolites were in the range of 0.4-1.0 ng/L.The recoveries of these analytes were in the range of 69.7%- 91.3%.This method exhibited high sensitivity,good repeatability,long-time stability and specificity,and could be used to detect amitraz and its metabolites in pond-water．