Abstract:Capparis masaikai Levl. with a native name Mabinlang is distributed in Yunnan of China. Its mature seeds are used as chinese medicine and posgess sweet taste. The sweet principle has been established to be a basic protein, hetein named mabinlin- The protein is extracted from lipid-free seed;bowier with water at 45℃, and precipitated with 60% saturation of (NH4)2SO4 at pH7, and then precipitated with 2 volumes of acetone from the dialyzed aqueous solution of protein. The solid albumin preparation contains 16.5% of N, and its yield is about 7.2% on dry weight of decorticated seeds. It contains four protein components A,B, C, D wit relative mobility of 0.46, 0.51, 0.73 and 0.89 respectively in 15% pdlyactlamide gel electrophoresis (pH 4.3). Thdse trohipo- nents are separated from each other by using CM-sephadex c-50 column chro- matography and thydroxyapatite column chromatography. Only the component D tastes sweet.