Abstract: species of microalga at exponential phase of growth be cultured in MAV substrate in the condition of water tempreture 20±1℃,salinity 34 and nature illumination. The microalga be collected by 4000～8000r/min centrifuge 10 minutes after 7 day's culute, the deposition has been rinsed with asepsis water 3 times be lyophilizated and then be freeze preserved(-4℃). The dry alga glomerules be homogenated with bead mill homogenizer for assay of total lipid and every fatty acid content each by chloroform methanol tecknique and gas chromatography. The assay results showed that the total lipid contents of the microalgae were more than 10% on dry weight except 4 species. Each class of microalgae was characterized by a specific fatty acid profile. The specific feature of Chlorophyceae were high concents of 16:0,16:1 (n 7),and 18:1(n 9)except N. oculatas which contain a little 16:3(n 3) and no 18:3(n 3),but contained high cocentration of 20:5(n 3). The specific features of Chrysophyceae were 14:0,16:0,18:3(n 3)and 22:6(n 3). The specific feature of Bacillariophyceae were high in contents of 14:0,16:0,16:1(n 7) and 20:5(n 3). The specific feature of Heterogloea sp. were high in contents of 16:0,16:1(n 7) and 20:5 (n 3) .