Abstract: Saline lake is one of the most favorable environments for developing hydrocarbon source rocks.Analyzing the group components and the saturate hydrocarbons in organic matters in the sediments from the bottom of the Qinghai Lake shows that the contents of total organic carbon in the sediments is high and that the sedimentary environment at the bottom of the Qinghai Lake is feeble oxidative.The organic matters mainly originate from the higher terrigenous plants around the Lake and the microbes and algaes in the Lake.Comparing the parameters such as distribution of carbon amount,carbon amount with peak value of content,carbon predominance index(CPI),and pristane/phytane ratio(Pr/Ph) in the immature organic matters in the sediments from the bottom of Qinghai Lake with those in mature hydrocarbon source rocks and crude oils from the typical salty lacustrine environment in our country can give us a set of valuable reference data about the maturity of organic matters.