Objective To investigate the clinical value of earlier period C reactive protein, hematocrit level and combining these two factors in predicting the severity in patients with acute pancreatitis. Methods Hct ad CRP within 24h after admission were evaluated, and the differences between severe acute pancreatitis and mild acute pancreatitis were analyzed. The effectiveness in predicting the severity in AP patients was evaluated by ROC curve. Results The levels of Hct and CRP in SAP group were significantly higher than those in MAP group (P<0.05). The sensitivity of CRP and Hct were 66. 67% and 50%, the specificity were 85.51% and 81.16%, the positive predictive values were 54. 55% and 40.91%, and the negative predictive values were 90. 77% and 86. 15%, respectively. The sensitivity of combi-ning CRP and Hct was 66. 67%, the specificity was 85.51%, the positive predictive value was 40. 91%, and the negative predictive value was 90. 77%. Conclusion The earlier period C reactive protein and hematocrit level have prognostic value, and combination use of these two factors are more sensitive in evaluating the severity in patients with acute pancreatitis.