Abstract: In this study, 18 kinds of fatty acids was separated on a C8 column by gradient elute using 2-(11H-benzoacarbazol-11-yl) ethyl4-methylbenzenesul-fonate(BCETS) as pre-column fluorescent derivatization reagent. The developed method was applied to analyze fatty acid composition in different fractions of Nitraria roborowskii Kom. The result showed that there existed abundant of unsaturated fatty acids in the parts of sarcocarps and leaves with percentages of 70.74% and 73.47%, respectively. The unsaturated fatty acids in seeds were relatively less than those in sarcocarps and leaves, which contributed only 57.21% to the total fatty acids. The composition of unsaturated fatty acids were mainly oleic and linoleic acids. The main unsaturated fatty acids in sarcocarps were oleic, linoleic and linolenic acids. The main unsaturated fatty acid in leaves was linolenic acid, and its percentage could reach 48.34% of the total fatty acids. To the best of our knowledge, this is the first time to study the fatty acid in N. roborowskii Kom, which can provide data support for its further development and application in food, medicine and quantity control.