Abstract: 1,4-dipalmitoyl hydroxyroline，a skin anti-aging agent used in cosmetics was synthesized from L-hydroxyproline and palmitoyl chloride. The influence factors，such as molar ratio of raw materials，the reaction time，temperature and media of reaction were studied. The appropriate reaction conditions were as follows：volume ratio of acetone 50%，molar ratio of L-hydroxyproline to palmitoyl chloride 1∶2.5，pH 9－10，reaction temperature 15 ℃，reaction time 4 h. After separation，a white solid powder with melting point of 81－85 ℃ was obtained.