Objective :To observe correlation among serum levels of cardiac troponin I (cTnI ) ,N terminal pro brain natri—uretic peptide (NT—proBNP) and cardiac function in pregnant patients with chronic heart failure (CHD) and its signifi—cance.Methods : A total of 82 pregnant patients with CHF treated in our hospital from Jun 2012 to Oct 2017 were enrolled as pregnancy + CHF group.Another 42 non—pregnant CHF patients (non—pregnant CHF control group ) and 42 normal pregnant women (normal pregnancy control group) were selected simultaneously .According to NYHA classification ,preg—nancy + CHF group was further divided into class II group (n＝36) and class III～IV group (n＝46).Serum levels of cTnI and NT—proBNP were measured and compared among above groups .The correlation among serum cTnI ,NT—proBNP levels and cardiac function class were analyzed in pregnant patients with CHF .Results : Compared with CHF control group and normal pregnancy control group ,there were significant rise in serum levels of cTnI [ (1.32 ± 0.46) ng／ml ,(0.08 ± 0.03) ng／ml vs.(2.39 ± 0.54) ng／ml] and NT—proBNP [ (4351.63 ± 374.82) pg／ml ,(204.92 ± 35.16) pg／ml vs.(6142.75 ± 415.06) pg／ml] in pregnancy + CHF group , P＝0.001 all ;those of CHF control group were significantly higher than those of normal pregnancy control group , P＝0.001 both .In pregnancy + CHF group ,compared with class II patients , there were significant rise in serum levels of cTnI [ (1.26 ± 0.37) ng／ml vs.(2.29 ± 0.52) ng／ml] and NT—proBNP [ (4103.51 ± 276.20) pg／ml vs.(6049.55 ± 427.06) pg／ml] in class III～IV patients , P＝0.001 all.Spearman correla— tion analysis indicated that serum levels of cTnI and NT—proBNP were significant positively correlated with cardiac function class in pregnant patients with CHF ( r＝0.732 ,0.884 ,P＜0.01 both).Conclusion :Serum levels of cTnI and NT—proBNP are significant positively correlated with cardiac function class in pregnant patients with CHD .Their detection can provide powerful evidence for early diagnosis and cardiac function assessment .