Abstract: A method analyzing reinforced concrete frames in fire by using beam element is presented in this paper.The temperature of the concrete and steel rebars of a reinforced concrete element cross-section is exactly decided by coding a user material subroutine and a user predefined field subroutine,and then the incremental strain-stress relation of concrete at elevated temperatures is determined.The comparison between the calculated results and ABAQUS concrete model results shows that the presented method is reasonable.