Objective To investigate the clinical value of serum cystatin C in the early renal function impairment in elderly patients wtih chronic congestive heart failure (CHF). Methods Serum cystafin Cwas measured in 60 cases with chronic CHF (CHF group), 40 cases with cardiovascular diseases and compensated heart function (compensated heart function group), and other 20 elderly normal volunteers(controlgroup). The correlation between cystafin C, B-type natriuretic peptide (BNP) and LVEF was evaluated. Results The levels of eystatin C in CHF group [(1.86±0.37)mg/L]was higher than that in compensated heart function group [(1.32±0.56) mg/L]and control group [(1.05±0.43) mg/L], P < 0.01. Cystatin C was positively correlated with BNP (r = 0.528,P< 0.01)and negatively correlated with LVEF (r=-0.463, P<0.01). In CHF group, the level of cystatin C and the incidence rate of renal failure was higher in the patients with BNP≥500 ng/L than those with BNP < 500 ng/L. Conclusions Cystatin C is a marker dearly impairment of renal function in elderly patients with chronic CHF. The more severe the heart failure, the more obvious the glomorular filtration function impairment shows.