Objective To observe the relation between functions of vessels of lower extremities and TCM syndromes differentiation in diabetes patients. Methods Totally 168 diabetics of Type II were differentiated into 5 syndromes

i.e. 29 cases of yin deficiency with excessive heat

41 cases of qi and yin deficiency

30 cases of yin and yang deficiency

37 cases of blood stasis in channels

and 31 cases of damp heat affecting the spleen

and 26 healthy people were involved in the control group. The peripheral vessel diagnostic system was adopted to get the toe photoplethysmogram （PPG） and ankle brachial index （ABI） to observe the blood perfusion of limb terminals and the functional state of lower limb arteries. The relation between function of vessels of lower extremities and TCM syndrome was analyzed. Results All the diabetic groups were related with the arterial blood supply of toe terminals. Diabetes was the main risk factor in affecting the terminal blood supply （P<0.05）

of which

the blood stasis in channels was the first risk factor

then it was the damp heat affecting the spleen

the yin and yang deficiency

the qi and yin deficiency

and the yin deficiency with excessive heat. The difference of ABI between the healthy control group and all the five patterns was significant（P<0.05 or P<0.01）. Conclusion The substantial pathogens such as blood stasis and damp turbidity are playing the important role in the vessel diseases of lower limbs of diabetes and deficiency is the basis of vessel diseases of lower limbs.