This study developed a simultaneous determination method for methylcyclosiloxanes(D3—D8) in surface water using liquid-liquid extraction(LLE) coupled with gas chromatography-tandem mass spectrometry(GC-MS/MS). The extraction efficiencies of different approaches, including solid-phase extraction(SPE) and LLE, were systematically compared for various cyclic methylsiloxanes. The method demonstrated excellent linearity(r>0.999 5) within the concentration range of 10~1 000μg/L. The limits of detection(LODs) ranged from 3 to 14 ng/L, with spiked recoveries of 74.0%~99.5% and RSD between 0.5% and 11.9%. Application of this method to surface water samples from a typical watershed revealed detectable concentrations of methylcyclosiloxanes(ND~194 ng/L) in most sampling sites. The contamination likely originated from wastewater discharges of fragrance/flavor manufacturing industries and domestic sewage in upstream catchment areas.