Objective：To investigate the correlation between serum 25-hydroxyvitamin D，serum parathyroid hormone levels and the biomarkers of heart failure （BNP and sST2） in patients with HFrEF. Methods：A total of 152 patients with HFrEF who were admitted to the Department of Cardiology of Nanjing Drum Tower Hospital from September 2017 to February 2018 were selected and 31 people with normal heart function was selected as the control group. levels of 25-hydroxyvitamin D were measured using electrochemiluminescence，parathyroid hormone levels were measured by chemiluminescence. The condation of chronic heart failure and lack of vitamin D，parathyroid hormone levels was analyzed. Results：Compared with healthy controls，patients with heart failure had significantly lower 25-hydroxyvitamin D levels and significantly increased PTH levels（P < 0.001）. Patients in HF with different 25-hydroxyvitamin D levels had a significant difference in heart function classification（P=0.003）. Patients with 25-hydroxyvitamin D deficiency had increased BNP and sST2 levels significantly，with statistical significance（P=0.016，P < 0.001）；Correlation analysis revealed that NYHA grades，BNP levels，sST2 levels were negative associated with 25-hydroxyvitamin D，VD/PTH respectively and positively correlated with PTH. Logistic multivariate regression analysis of independent risk factors for heart failure revealed that both 25-hydroxyvitamin D and PTH levels were independent risk factors for heart failure. Conclusion：The 25-hydroxyvitamin D levels in patients with HFrEF are lower than those in healthy people，and serum parathyroid hormone levels are higher than those in healthy people. The level of 25-hydroxyvitamin D in patients with heart failure was negatively correlated with the severity of cardiac function. PTH levels were positively correlated with the severity of heart function. 25-hydroxyvitamin D/PTH levels were negatively correlated with the severity of heart function；and 25-hydroxyl vitamin D and PTH levels are independent risk factors for heart failure.