Benomyl, one of the known endocrine disrupting chemicals, was analyzed to understand the fate in the nature. Water, sediment and biota samples are acidified to hydrolyze benomyl into carbendazim then followed by extraction and concentration. The concentrations of carbendazim in the samples were determined by liquid chromatography/time-of-flight mass spectrometer. Analysis data showed that certain amount of carbendazim was accumulated in sediment. On the contrary, no sign of accumulation in biota was observed probably due to the increased degradation rate in vivo. It is, however, that no one can claim carbendazim is not harmful to biota, since carbendazim may give a negative effect against organisms at the point of intaking.