Pesticides　exert　a　long-term　negative　influence　on　the　aquatic　organism　and　even　the　aquatic　environment.　It　is　necessary　to　find　some　potential　biomarkers　to　give　insight　into　the　pesticides　pollution　and　provide　a　rapid　,　sensitive　,　early-warning　method.　In　this　study　,　ultra-performance　liquid　chromatography　with　quadrupole-time-of-flight　mass　spectrometry(UPLC-QTOF-MS)　was　applied　to　analyze　the　effect　of　pesticides　on　the　metabolomics　in　liver　and　brain　of　Crucian　carp.　Three　pesticides,　namely　trichlorfon,　beta-cypermethrin　and　imidacloprid　were　investigated　,　respectively.　Data　was　collected　by　masslynx　software　in　MSE　mode　,　analyzed　by　UNIFI　software　for　automatic　detection　and　data　filtering,　compared　to　the　online　metabolome　database.　The　metabolic　difference　of　liver　was　more　significant　than　that　of　the　brain.　The　triglycerides　(TGs)　species　were　identified　as　the　different　metabolites.　Among　these　three　pesticides,　imidacloprid　had　the　most　significant　influence　on　the　metabolism　of　TGs.　The　low　concentration　of　acute　exposure　induced　the　accumulation　of　TGs　in　the　liver,　and　the　relationship　between　the　content　and　the　exposure　concentration　was　in　line　with　the　growth　trend　of　Michaelis-Menten　equation.　The　results　showed　that　TGs　can　sensitively　reflect　the　low　concentration　exposure　of　imidacloprid　pesticides　(＜=　20　ng/mL)　in　a　short　period　of　time　(＜=　2　h)　,　which　can　be　used　as　a　potential　biomarker　to　investigate　the　toxicity　of　imidacloprid　to　aquatic　organisms　,　and　help　to　establish　a　new　method　for　estimation　the　pesticides　contamination　in　aquatic　environment.