Disclosed is a method for determination of an activity of .gamma.-glutamyl transpeptidase, leucine aminopeptidase, alanine aminopeptidase, cystine aminopeptidase, X factor as a coagulation factor, thrombin, plasmin of plasminogen series, kallikrein, chymotrypsin, alkali phosphatase, N-acetyl glucosaminase and amylase, by allowing a particular substrate to act on the enzyme to thereby form an enhancer; oxidizing a chromogen by an oxidase in the presence of the enhancer and oxygen to form a pigment; and determining the pigment. Also disclosed is a test composition for carrying out the determination.