The maximum number of carbon atoms adsorbed at edge dislocation was calculated using a model based on Boltzmann distribution. The number of carbon atoms adsorbed by edge dislocation increases with bulk concentration increasing and temperature decreasing. When the interfacial energy was chosen as 0.2J/mol, the maximum radius of carbon depleted zone is smaller than the critical radius required for displacive nucleation at 700K, however, larger than the critical radius at 600K. Moreover, the radius of carbon depleted zone around the dislocation at 600K is larger than that at 700K. It seems that bainite may nucleate by a displacive mechanism at lower temperature.