OBJECTIVE： To investigate the effects of Enalapril maleate folic acid tablets on carotid atherosclerosis in H type hypertension patients with type 2 diabetes mellitus （T2DM） and its potential mechanism. METHODS： In prospective control study， 182 H type hypertension patients with T2DM were selected from Chongqing People’s Hospital during Jan. 2014-Jan. 2016， and then randomly divided into observation group and control group， with 91 cases in each group. All patients received basic or hypoglycemic treatment of premixed insulin； observation group was additionally given Enalapril maleate folic acid tablets （containing enalapril maleate 10 mg， folic acid 0.8 mg in each tablet） orally， one tablet， qd； control group was additionally given Enalapril maleate tablets （containing enalapril maleate 10 mg in each tablet） orally， one tablet， qd. Treatment course lasted for 12 months. The levels of blood pressure， plasma homocysteine （Hcy）， fasting blood glucose （FBG）， C-reactive protein （CRP） and carotid plaque score were detected in 2 groups before treatment， 12 months after treatment. RESULTS： Compared to before treatment， SBP and DBP of 2 groups were decreased significantly in 2 groups after 12 months of treatment （P＜0.05）； there was no statistical significance between 2 groups （P＞0.05）. The levels of plasma Hcy， FBG and CRP， carotid intima-media thickness and carotid plaque integral in observation group were significantly lower than control group （P＜0.05）. CONCLUSIONS： Enalapril maleate folic acid tablets can relieve inflammation by reducing plasma Hcy， FBG and CRP so as to treat carotid atherosclerosis in H type hypertension patients with T2DM.