Abstract: Sulfoquinovosyl diacylglycerol(SQDG) is a sulfur-containing glycolipid. It is widely distributed in photosynthetic membranes of all higher plants, mosses, ferns,algae and most photosynthetic bacteria. The content of this lipid in photosynthetic membranes depends on the biological species. In higher plants, the level of this compound amounts to 4% of total lipids. However, the level of SQDG changes greatly in algae, amounting to 10%-70% of total lipids. SQDG is synthesized mainly in the inner envelope membrane. The enzyme catalyzing the reaction is UDP-sulfoquinovose:diacylglycerol sulfoquinovosyltransferase. SQDG seems to play an important role in photosynthetic process. It has been reported that SQDG was associated with several protein complexes in photosynthetic membranes such as the chloroplast CF0-CF1 ATPase, the LHCⅡ-apoproteins and native D1/D 2 heterodimers. In addition, SQDG is related to the stress response of plants. Under the phosphate limitation conditions, SQDG can partially compensate PG deficiency. In recent years,SQDG has been found to be effective against the activities of eukaryotic DNA polymerase and HIV-reverse transcriptase.