Objective:To find the relationship between insulin-resistance and Syndrome Differentiation type (SDT) in hypertensive patients.Methods: Two hundred and nine patients of early stage hypertention with no complications of heart, brain or kidney were selected and classified into 4 types according to SDT, the Liver-Fire exuberant type (A), the Phlegm-Dampness abundant type (B), the Yin-Deficiency and Yang-Excess type (C) and the Deficiency of both Yin and Yang type (D). Their insulin sensitivity was examined and compared with that of 40 healthy subjects.Results:(1) Compared with the healthy subjects, all hypertensive patients had apparent insulin resistance (P<0.05).If the insulin sensitivity of healthy subjects was defined as 1.00, that of patients of type A, B, C and D were 0.54, 0.58, 0.65 and 0.80 respectively. (2) The insulin sensitivity of patients in the 4 SDT groups were compared and no significant difference was found in comparison between group A, B and C, while significant difference was found when the other three groups were compared with group D (P<0.05), the insulin sensitivity of type D was close to that of the healthy subjects. (3) The fasting blood insulin of type D was obviously lower and the insulin sensitivity of type D was obviously higher than that of the other three types as a whole (P=0.0001). (4) Multivariate regression analysis demonstrated that insulin sensitivity was closely correlated with SDT (P=0.0001). Conclusion: Insulin resistance is one of the pathological basis for SDT in hypertension. Objective: To find the relationship between insulin-resistance and Syndrome Differentiation type (SDT) in hypertensive patients. Methods: Two hundred and nine patients of early stage hypertention with no complications of heart, brain or kidney were selected and classified into 4 types according to SDT, the Liver-Fire exuberant type (A), the Phlegm-Dampness abundant type (B), the Yin-Deficiency and Yang-Excess type (C) and the Deficiency of both Yin and Yang type (D) was compared with that of 40 healthy subjects. Results: (1) Compared with the healthy subjects, all hypertensive patients had apparent insulin resistance (P <0.05) .If the insulin sensitivity of healthy subjects was defined as 1.00, that of patients (2) The insulin sensitivity of patients in the 4 SDT groups were compared and no significant difference was found in comparison between groups A, B and C, while significan The difference was found when the other three groups were compared with group D (P <0.05), the insulin sensitivity of type D was close to that of the healthy subjects. (3) The fasting blood insulin of type D was obviously lower and the insulin sensitivity of type D was obviously higher than that of the other three types as a whole (P = 0.0001). (4) Multivariate regression analysis characterized that insulin sensitivity was closely correlated with SDT (P = 0.0001). Conclusion: Insulin resistance is one of the pathological basis for SDT in hypertension.