Objective To investigate the changes and clinical significance of thyroid hormones function in elderly patients with chronic heart failure. Methods A total of 76 elderly patients with chronic heart failure were divided into different groups according to NYHA categorization: NYHA Ⅱ group (25 patients), NYHA Ⅲ group (28 patients) and NYHA IV group (23 patients). Thirty non-heart failure elderly subjects served as control group. T₃, T₄, FT₄, FT₃, TSH were tested by radioimmunoassay. Results Compared with T₃ and FT₃ levels [(2.34±0.52)nmol/L and (4.27±0.64) pmol/L respectively] in control group, T₃ and FT₃ levels[(1.28±0.51) nmol/L and (3.01±0.78) pmol/L respectively] in NYHAⅡ group were decreased (P＜0.05); and with the deterioration of cardiac function functional class Ⅲ-Ⅳ (P＜0.01), patients showed T₃ and FT₃ levels [ (0.87±0.43) nmol/L and (2.42±0.61) pmol/L respectively] in NYHA Ⅲ group, and [ (0.60±0.36) nmol/L and (2.09±0.71) pmol/L respectively ] in NYHA IV group. Conclusions T₃ and FT₃ play an important role in chronic heart failure, can serve as the early predictors in elderly patients with chronic heart failure.