The major saturated fatty acids (SFA) in Chlorella sp. Y8-1 were palmitic acid (16:0) and stearic acid (C18:0). The major monounsaturated fatty acid (MUFA) was oleic acid (18:1). It indicated that Chlorella sp. Y8-1 accumulated a high proportion of SFA and MUFA to 50% of the total lipid content. Compared to the commonly used soybean oil as feedstocks for biodiesel production in the US, the biodiesel derived from microalgae lipid in this study would be more saturated and provide a higher cetane number (CN), lower NOx emissions, shorter ignition delay time, and higher oxidative stability. Numerous fatty acids could not be identified in this study, because unsaturated fatty acids largely prevail in lipids.