A case of far advanced gastric cancer with multiple liver metastasis (H3) was treated with transarterial intermittent chemotherapy (5-FU: 250 mg/week, Farmorubicin: 10 mg/4 weeks, MMC: 4 mg/2 weeks) and intradermal administration of low molecular lipopolysaccharide (LPSp) extracted from Pantoea agglomerans. The CT examination and endoscopy showed regression of the tumor and the patient was discharged from the hospital. LPSp was given at the concentration of 0.1 microgram initially, and the dose was gradually increased. Finally, the dose of LPSp was increased up to 70 micrograms. No serious side effect except fever was observed. The serum TNF-alpha levels were elevated and, histologically, CD 8(+) lymphocyte dominantly infiltrated around the tumor. These findings clearly indicated the immunological anticancer effect of LPSp. Intradermal administration of LPSp is a promising new adjuvant therapy to improve QOL without serious side effect.