Objective： To evaluate the efficacy and toxicity of concurrent chemoradiotherapy for patients with locally advanced unresectable extrahepatic cholangiocarcinoma. Methods: Thirty-eight patients with locally advanced unresectable extrahepatic cholangiocarcinoma admitted in Shaoxing People's Hospital from February 2007 to February 2012 were enrolled in the study. They were randomized into sequential chemoradiotherapy （n=19） or concurrent chemoradiotherapy group （n=19）. All patients were treated with intensity modulated radiation therapy （IMRT）. Patients in concurrent chemoradiotherapy group received the regimen of gemcitabine plus oxaliplatin. Tumor response and adverse effects were observed periodically. The primary end points were disease progression-free survival （PFS） and overall survival （OS）. Results: The response rates of sequential chemoradiotherapy and concurrent chemoradiotherapy groups were 42.1% （8/19） and 632% （12/19）. The disease control rates of them were 78.9% （15/19） and 84.2% （16/19）， respectively. The median PFS of sequential chemoradiotherapy group and concurrent chemoradiotherapy group was 8.3 （95%CI: 7.6-9.0） and 10.4 months （95%CI: 9.4-11.4， P=0.037）， and the median OS in two groups were 14.2 （95%CI: 12.6-15.8） and 15.6 months （95%CI: 14.2-17.0， P=0.095）， respectively. The major adverse reactions were controllable hematology toxicity and gastrointestinal reaction. There was no significant difference in incidence of adverse reactions between two groups （P>0.05）. Conclusion: Sequential chemoradiotherapy and concurrent chemoradiotherapy may improve PFS and OS in patients with locally advanced unresectable extrahepatic cholangiocarcinoma， and both are well-tolerated. In addition， concurrent chemoradiotherapy might provide additional PFS benefit and would be preferable.