To date, curative treatment of pancreatic cancer is surgery.But patients with operable indication are rare, most of patients present with locally advanced or general advanced stage at diagnosis. Thus the majority of patients need chemotherapy.But efficacy outcomes have not seemed to increase overall survival comparing with none treated control group.In Korea the incidence of pancreatic cancer increases steadily. Prognosis is poor. So now the effective treatment is necessary.There are no phase 2 trialsabout combining gemcitabine and TS-1 against advanced pancreatic cancer.according to phase 1 trial of advanced pancreatic cancer (nakamura et al)toxicities more than 3 grade are neutropenia, anemia, thrombocytopenia, anorexia, etc that can be treated.Phase 1 trial is not study to evaluate the response rate. But among 21 patients who can be evaluated the response rate, 10 patients have Partial response or Complete response.This combination therapy seemed to havetolerable toxicity and remarkable therapeutic effect for locally advanced or metastatic pancreatic cancer.So therapy combining gemcitabine with TS-1 is expected synergic and additional effect.