Aim To investigate the effects of zopiclone on patients of typeⅠessential hypertension combined with dyssomnia and explore its mechanism of action. Methods Patients with essential hypertension combined with dyssomnia were included and randomly assigned in two groups:non-drug treatment of patients were provided with lifestyle management advices including control of salt intake, physical exercise, prohibiting use of cigarettes and alcohols and improving food diversity; patients in the zopiclone group were given zopiclone along with the same lifestyle advices. The Pittsburgh Sleep Quality Index (PQSI), blood pressures (BPs), plasma renin activity (PRA), blood concentration of angiotension Ⅱ (AngⅡ) and aldosterone (ALD) before and after the treatment were compared. Results Zopiclone showed significant course-dependent effect of lowering PSQI and improving quality of sleep (P<0.05, P<0.01, respectively), the outcome of the zopiclone group was better than non-drug group (P<0.001). After 6 weeks’ therapy, SBP and DBP of the zopiclone group patients were lower than the non-drug group (P<0.05, P<0.01). Meanwhile, improvements in PRA, AngⅡ and ALD were more significant as well compared to the non-drug group (P<0.05, P<0.01). Conclusion Zopiclone is effective in controlling the blood pressures of patients with typeⅠessential hypertension combined with dyssomnia, and deactivating RAAS by improving sleep-disorder is possibly involved in its effects.