The combined effect of anticancer agents (Mitomycin-C, cyclophosphamide, or 5-fluorouracil) and anaerobic Corynebacterium liquefaciens on subcutaneously induced solid Ehrlich carcinoma in mice was examined. Mitomycin-C and cyclophosphamide were given intraperitoneally on day 7 after inoculation of tumor cells. 5-Fluorouracil was administered intraperitoneally for 7 consecutive days from day 9 to 15. C. liquefaciens was given in two ways, intraperitoneally and intratumorally. Its injections were made on days (--7, --5), (--4, --2) (+2, +4), or (+5, +7) in the intraperitoneal groups and in every way varying from (+9, +10) to (+19, +20) days in the intratumoral groups. The best result was observed in combination of C. liquefaciens and 5-fluorouracil in the intraperitoneal groups and that of C. liqlefaciens and cyclophosphamide in the intratumoral groups. Although the results were not necessarily good, probably due to the poor design on time schedule of C. liquefaciens, they partly confirm the hypothesis that the activity of conventional anticancer drugs can be potentiated by a non-specific immunostimulation by anaerobic C. liquefaciens in the solid tumor of mice same as in the ascitic tumor reported previously.