The aim of this study was to observe the changes in the serum Adiponectin (APN) levels and Left Ventricular Hypertrophy (LVH) in hypertensive patients before and after telmisartan treatment. Two hundred and forty hypertensive patients complicated with LVH were divided into a telmisartan group and an amlodipine group. The changes of these patients' blood pressure, APN, and Left Ventricular Mass index (LVMI) treatment before and 12 w after treatment were compared. The systolic and diastolic blood pressures in both groups were significantly lower than those before treatment (P<0.01). The difference in diastolic blood pressures between the two groups was not statistically significant (P>0.05). Serum APN levels in the telmisartan group were significantly higher than those before treatment (P<0.01), while LVMI was significantly lower than before (P<0.01). Serum APN levels and LVMI had no significant changes in the amlodipine group before and after treatment (P>0.05). Compared with amlodipine, telmisartan significantly increased the serum APN levels and significantly reversed the Left Ventricular Remodeling (LVRM) while reducing the blood pressure.