 Cholangiocarcinoma CCA, cancer of the bile duct, is the first cause of cancer death of the people in the northeast of Thailand. The incidence of CCA in this region is highest not only in the country but in the world. CCA is a slow growing but highly metastatic tumor. At present, there is no standard chemotherapy or effective treatment for CCA. Most of the patients have short survival after diagnosis. Strong evidences from in vitro, animal and clinical studies indicate that vitamin D can prevent and control growth of cancer. Our preclinical studies in CCA cell lines, animal and patient tissue culture indicate that vitamin D effectively reduce growth of CCA. Supplementation of vitamin D to chemotherapeutic drugs enhance drug toxicity and better response. At present, there are several clinical trials in USA on supplementation of vitamin D or its analogs to cancer patients. The side effect or toxicity of using vitamin D supplementation is low, some patients had stable disease and some had good response. The current study is set up a clinical trial phase II of vitamin D calcitriol in combination with 5-fluorouracil, Mitomycin C and Leucovorin in an open label-non-randomized study to evaluate the tumor response in patients with advanced intrahepatic cholangiocarcinoma. This study will provide an alternativeeffective chemotherapy treatment for CCA patients. Better survival and improved quality of life are also expected. 