Abstract: Emerging studies have shown the important bioactivities of hydroxy unsaturated fatty acids(HUFA). The bioproduction of HUFAs is highly specific and environmentally friendly, which has become one of the main preparation methods of HUFA. The sources, functions and applications of two most studied microbial HUFAs, namely 10-hydroxy-12-octadecenoic acid(10-HOE) and 13-hydroxy-9-octadecenoic acid(13-HOE), are first discussed. Then, the research progress of linoleic acid hydratases(LHT), one type of microbial enzymes responsible for the synthesis of 10-HOE and 13-HOE, is reviewed. Finally, the further researches of the bioactivities and biosynthesis of HUFA are proposed, in which the bioconversion efficiency of HUFA with LHT can be improved based on the theory of colloid and interface chemistry.