Objective To study the variety and the action of inflammatory cytokines and the relevant anti-inflammatory factors in acute pancreatitis (AP). Methods The authors observed the change of peripheral blood IL-6 and sTNFR in 41 patients with mild and severe AP in two groups on 1, 5, 14d after acute attack by ELISA. Results All cases recovered gradually in mild group (n＝22) after five days. Twelve patients improved gradually in severe group (n＝19) after 5-7 days. The level of sTNFR increased markedly in 2 groups at 1, 5, 14d(Ｐ＜0.001), and that of the severe group was markedly higher decreased gradually (Ｐ＜0.01). The level of IL-6 increased apparently only in severe group on 1d, 40.38 pg/ml∶12.4 pg/ml, (Ｐ＜0.001). The levels of IL-6 and sTNFR correlated respectively with severity of AP. Conclusion These results show that peripheral blood IL-6 and TNFα are useful index to supervise the severity and conversion and final results of AP.