【Objective】 To study the effect of primary hypertension with depression on cognitive function of patients. 【Methods】 In this study, 47 patients with both primary hypertension and depression, 50 patients with primary hypertension from Feb. 2013 to Jan. 2015 and 40 normal controls were enrolled. Montreal Cognitive Assessment Scale (MoCA) was performed to evaluate their cognitive function. Multivariate logistic regression analysis was used to investigate the related factors of damage of cognitive function. 【Results】 The scores of visual space, executive function, language and abstract, and the total score of MoCA in the primary hypertension with depression group were significantly lower than those in the control group (P < 0.05). The total MoCA score in the primary hypertension group was significantly lower than that in the control group (P < 0.05). The result of multivariate logistic regression analysis showed that age, pulse pressure (PP) and the score of Hamilton's Depression Scale (HAMD) were independent risk factors of cognitive impairment (P < 0.05). 【Conclusions】 Compared with people with simple primary hypertension and healthy adults, the cognitive function in patients with primary hypertension and depression obviously decreases. And older age, high PP and high HAMD score could significantly increase the risk of cognitive decline.