In a randomized controlled study of chemotherapy (CDDP 100 mg/m2 day 1, VDS 3 mg/m2 day 1, 8, 15) vs. immuno-chemotherapy combined with PSK 3 g/day for adenocarcinoma of the lung (stage III, IV, p. s. 0, 1, 2), response rate for 169 cases with completed extramural review was 14.2%. As for the response rates for 138 complete cases, the chemotherapy group showed 17.9%, and the immuno-chemotherapy group was 16.9%. MST were 330 days and 331 days, respectively. In stage III cases, the response rates were 11.1% in the chemotherapy group and 37.5% in the immuno-chemotherapy group (p = 0.046). MST were 457 days (65.3 weeks) and 576 days (82.3 weeks), respectively. In terms of survival curve, it was suggested that the immuno-chemotherapy group was superior to the chemotherapy group (logrank test p = 0.075), but in stage IV cases, there was nothing outstanding in the immunochemotherapy group.