Objective: To observe the changes of endothelin (ET), nictric oxide (NO), atrial natriuretic pepfide (ANP) and endogenous digitalis-like substance (EDLS) atrial natriuretic peptide (ANP), endogenous digitalis-like substance (EDLS) in plasma before and after treatmeat with arotinolol, imidapfil and enalapfil, to explore the effects of antihypertensive treatment on neuroendocrine factors in hypertensive patients. Methods: 90 patients with moderate essential hypertension were divided randomly into three groups and treated with arotinolol (20~30mg/d), imidapril (5~10mg/d) and enalapfil (5~10mg/d) respectiveely.Plasma levels of ANP, EDLS, ET and NO were measured before and after treatment. Results: After six weeks therary, blood pressure decreased significantly in three group (P<0.01 ), and there was no significant difference among three groups (P>0.05). After treatment, the level of ANP in arotinolol group increased (P<0.001), while that of ET and NO didn’t change (P>0.05); The plasma concentration of ET and ANP in imidapril and enalaprit groups decreased and that of NO increased significantly (P<0.05). The level of EDLS decreased significantly in every group (P<0.05). Conclusions: All the three drugs can decrease blood pressure effectively. The efficacy of antihypertensive drugs has relation with the changes of neuendocrine substance above.