AIM:To research the bulbar conjunctival microcirculation of patients with primary hypertension.METHODS:With slit-lamp digital camera,we observed vascular size and capillary hemangioma for normal blood pressure(88 cases 176 eyes)and primary hypertension(70 cases 140 eyes).RESULTS:The positive rate of primary hypertension group was 94.3%;in the normotensive control group,the positive rates of the elder and young adults respectively were 19.3%,15.5%.There was a significant difference between the primary hypertension group and normal blood pressure group,while the difference between the two normal blood pressure groups was not obvious.CONCLUSION:Taking capillary hemangioma and vascular size as indexes is easy to reflect the positive signs of bulbar conjunctival microcirculation.