A photometric procedure for the determination of N-carbobenzoxy-L-glutamylcholine (I) was established by the use of triiodide reagent and ethylene dichloride. For the separation of (I) from choline chloride a preliminary examination was made on the ion exchange column chromatography using Amberlite IR-120 and paper chromatography using a developing solvent containing n-butanol・acetic acid・water (4 : 1 : 1). In the column chromatographic method. (I) and choline are absorbed on Amberlite IR-120,the former is eluted with 3% NaCl・0.1N HCl, then the latter is eluted with 1N NaOH. The recovery from column chromatography was found to be about 95-103% and that from paper chromatography to be about 95%. An aqueous solution (I) is comparatively unstable, the reaction velocity coefficients obtained by column chromatographic method are k_1(25℃)=12.06×10^<-4>day^<-1> and k_1(50℃)=62.51×10^<-4>day^<-1>. Therefore, in order to preserve (I) a high degree of dried state is needed. When (I) was heated in a powdery state, only 0.2% of free choline was produced at 120℃ for 30 min.