Abstract: Objective:To observe the change of serum Cystatin C(Cys C) level in patients with chronic heart failure(CHF)，and investigate the significance between Cys C level and cardiac function． Methods:The subjects were divided into CHF group(n =80) and normal control group(n =30)． Severity of CHF was according to New York Heat Association(NYHA) heart functional classes． Serum Cyst C level was measured by ELISA assay． The left ventricular ejection fraction and left ventricular end diastolic diameter were detected by ultrasonic cardiogram． The mortality and re-hospitalization for chronic heart failure were recorded during hospitalization and discharge from hospital within 6 months． Results:The level of serum Cys C in CHF group was higher than that in control group(P 0． 01)，it was increased with the higher class of NYHA heart functional classification(P 0． 01)． Serum Cys C level had negatively correlated with left ventricular ejection fraction，but positively correlated with left ventricular end diastolic diameter(P 0． 05)． There was no statistical difference of the mortality between higher CysC level group and lower Cys C level group(P ＞0． 05)． During following-up for 6 months， the re-hospitalization for chronic heart failure and fatality were higher in patients with higher Cys C level than in those with lower Cys C level(P 0． 05)． Conclusions:Serum Cys C level is a potential biomarker for diagnosis of chronic heart failure，and it can reflect the recent prognosis of chronic heart failure．