In this study we investigated temporal changes in both the endocrine system and immunity in rats under immunochemotherapy with 5-FU and Krestine (PSK). This immunochemotherapy was performed on two types of groups, non-cancer-bearing rats and cancer-bearing rats. As hosts, inbred strain WKA/HA 5-week-old male rats and as tumors, transplantable ascitic liver cancer KDH-8 cells were used. Our results indicated that 1) in the non-cancer-bearing rats, 5-FU administration led to an increase in serum cortisol and IAP, however, PSK concurrent administration clearly lowered the levels of cortisol and IAP; 2) in the cancer-bearing rats, the levels of ACTH, cortisol and IAP increased as the cancer progressed, but in the immunothemotherapy administration groups these levels were lower; 3) the immunothemotherapy administration group had greater effects on both tumor growth and liver metastasis.