Abstract: GASCP was produced from the isoelectric liquor by evaporative crystallization process,in which a large amount of impurities such as pigments,(NH4)2SO4 remained.This made the product cannot be further purified to produce MSG.The solution mediated transformation(SMT) of L-glutamic acid is one of the ways to improve the quality of the GASCP.The effects of temperature,pH,ratio of GASCP/water and the use of activated carbon on the SMT of GASCP were investigated.Based on the researches,the ideal conditions for SMT of GASCP were determined as follows: temperature was 95℃,pH 4.5,the ratio of GASCP/water was 1∶ 2.5,the mount of activated carbon was 1%.