Abstract: In this paper, the organic matter parameters in the surface seawater of Zhoushan sea area are studied.The collected surface seawater samples were eluted with n-hexane and then subjected to rotary evaporation and nitrogen purge to the GC-MS for analysis.The results show:the distribution of bimodal dominant carbon and the posterior peak dominant carbon are the peak types, Pr and Ph abundance is relatively high for the surface seawater may be polluted by oil.Carbon preference index (CPI) is around 1, combined with Σn-Alk/C₁₆, terrigenous/aquatic ratio (TAR), Pr/Ph, odd-even predominance (OEP) and other parameters which indicated the presence of oil pollution.The distribution trends of the terpanes at each station were similar in the Zhoushan sea area, and most of the stations detected 18α(H)-oleanane, Ts/Tm, C₃₁αβ(S/(S+R)), C₃₂αβ(S/(S+R)), C₂₉ααα (S/(S+R)) which were little high that maybe influenced by the oil pollution in Zhoushan sea area.