Objective:To observe the features on cytochemical changes in different tongue coatings.Method:7 tongue epithelial cytochemistry indexes in 33 cases of white tongue coatings, 35 cases of yellow tongue coatings were detected with microspectrophotometry,and compared according to the syndrome differentiations.Result:in white tongue coating group,all of the indexes but G 6 PDH were lower than those In normal group,and LDH,MDH and ACP were significantly different ( P