Abstract: ObjectiveTo investigate the significance of carbohydrate antigen 19-9 (CA 19-9), carcinoembryonic antigen (CEA) and cancer antigen 125 (CA125) levels for predicting response and survival in unrespectable pancreatic cancer (UPC) treated with concurrent chemoradiotherapy. MethodsWe retrospectively reviewed data from 24 patients with UPC between 2004 and 2009. CA 19-9, CA125 and CEA levels (pre-, post-treatment and intra-treatment every week) and their decline were analyzed for radiologic response and overall survival. ResultsOf all patients，response rate was 25%，the median survival time (MST) was 8.4 months . Pretreatment CA 19-9 ≥1 000 u/ml (MST, 12 vs. 6 months; P=0.039), CA125≥50 u/ml(MST, 12 vs. 6 months; P=0.04), were unfavorable prognostic factors. Post-treatment tumor marker (CA19-9 or CA125 or CEA) decline ≥50% (MST, 12 vs. 6.0 months; P=0.005) was prognostic factors. Intra-treatment all patients were dived into “up-tendency” and “down-tendency” according to tumor marker (CA19-9 or CA125 or CEA) levels every week. MST was 6 months and 15 months and response rate was 0 and 50% in “up-tendency” and “down-tendency” group. ConclusionCA19-9, CEA and CA125 may possibly serve as a predictor for response and survival in unresectable pancreatic cancer patients treated with chemoradiotherapy.