Reagent for analysis of triglycerides contained in blood serum is provided, which comprises lipases and monoglyceride lipases capable of acting on monoglycerides having substrate specificity and capable of catalyzing the following enzymatic reaction: monoglyceride+H.sub.2 O.fwdarw.glycerol+fatty acids. The glycerol or fatty acids are measured to learn an amount of the triglycerides or fatty acid by any known analytical method.