Abstract: Based on the distributing curve model of curvature and the theory of structural mechanics,this paper derives formula of computing the deformations of reinforced concrete beams and steel fiber reinforced concrete beams,puts forward uniform formula of equivalent plastic area length fitted to reinforced concrete beams and steel fiber reinforced concrete beams by combining with test data,studies the effect of steel fibers on equicalent plastic area leagth of reinforced concrete beam.These results show that stee...