Thirty patients with obstructive jaundice were investigated for serum complement-3 (C3) and plasma fibronectin (FN).The levels of C3 and FN of the juandiced patients were higher than that of thirty patients without obstructive jaundice (Ｐ＜0.01). As compared to pre-operation, the level of C3 of the jaundiced patients decreased obviously within two weeks after operation(Ｐ＜0.01), and recovered in the third week after operation. The level of FN of the juandice patients decreased evidently within one week(Ｐ＜0.01), and recovered in the second week after operation. However, the levels of C3 and FN of the patients without obstructive jaundice changed slightly after operation (Ｐ＜0.05). The high levels of C3 and FN of jaundiced patients may be relative to the latent infection. Consumption and immune imparing may be the reasons of C3 and FN to decrease.