This paper presents a numerical investigation of pullout behavior of fiber reinforced polymer (FRP) bar from concrete matrix. As an attempt to capture the debonding process, a progressive damage model is used. Interfacial stress distribution for different load level is analyzed. The effects of embedded length. diameter of FRP bar and bond strength on the load-loaded end displacement are studied. The numerical results indicate that the bond stress decreases gradually from loaded end to embedded end along embed-embedded bar length. The debonding initially starts from loaded end and propagates to embedded end as load increasing. The embedded length and bond strength affect the load-loaded end displacement curves significantly while the diameter of the FRP bar has no obvious effect on these curves. The numerical results have a good agreement with the experimental investigation. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.