Objective To explore the differences of tongue characteristics in patients of functional constipation of different excessive syndromes. Methods Totally 224 cases were collected with 90 cases of heat accumulation

68 cases of cold accumulation and 66 cases of qi stagnation. Tongue-surface integrated instrument was used to record and analyze the tongue feature data. The HSV model was used to record tongue texture（cracks

pricks

tooth marks

fat or thin） index and tongue coating texture（thickness

moisturizing

greasy

exfoliating） index to compare the differences in tongue picture of different syndrome types. Results Red tongue and thin yellow coating were more common in heat accumulation constipation; cold accumulation constipation were mostly pale and fat tongue

thin white coating

and tooth marks were more common; qi stagnation constipation was more common in pale red tongue and thin white coating. Tongue feature data showed that the cold accumulation constipation had the largest chroma and lightness value

the smallest saturation value

and the tongue coating chroma and lightness value and tooth mark index were the largest（P<0.05 or P<0.01）. The crack index and exfoliation index of heat accumulation were the largest（P<0.05 or P<0.01）. Conclusion In excessive type functional constipation

white tongue and tongue coating are common in cold accumulation constipation

and it is more prone to have tooth marks tongue. In heat constipation

cracked tongue and exfoliation tongue coating are more common.