Abstract: Objective To investigate the changes of serum insulin-like growth factor-1（IGF-1） and nitric oxide（NO） levels in patients with essential hypertension（EH） before and after valsartan treatment. Methods Serum IGF-1 levels and NO level were measured by radioimmunoassay and nitrate reductase method respectively in 50 patients with essential hypertensions before and after 6 months treatment. 25 normotensive served as controls. Results Base line IGF-1 serum level were higher in EH than in normal controls （13.36±3.36 vs 9.67±2.57 nmol/L,P ＜0.01）,whereas NO serum level was lower（61.94±18.02 vs 77.15 ±13.50 μmol/L P ＜0.01）. The IGF-1 Serum level were higher in EH with LVH than in those without LVH（14.15±4.23 vs 11.57±3.10 nmol/L,P ＜0.01）,while NO serum level were lower in EH with LVH than in those without LVH（56.20±17.15 vs 67.68±18.97 μmol/L P ＜0.05）. After six months treatment of valsartan,serum IGF-1 levels tends to fell 10.85±2.97 nmol/L（ P ＜0.01）,serum NO levels increase to 72.07±15.45 μmol/L（ P ＜0.01）,left ventricular mass index（LVMI） was reduced to 111.13±15.27 g/m 2（ P ＜0.01）. Conclusion These data indicate that serum IGF-1 levels are increased in essential hypertension,with serum NO levels decreased,especially in EH with LVH. Valsartan decreases serum IGF-1 levels and increases serum NO levels in patients with essential hypertension,when the LVH was reversed.