Abstract: The effect of cooling process after deformation on V micro-alloyed and V-free rebar was studied. The thermal simulation experiments were carried out with different cooling processes after deformation. The transmission electron microscopy and energy spectrometer were employed to observe and analyze precipitation of the tested steels. The results show that air cooling after high temperature deformation benefits the fine VC precipitation for rebar containing V,providing a better precipitation strengthening effect.For V-free rebar,holding for 30 min at 650 ℃ after high temperature deformation is beneficial to the precipitation of nanoscale cementite. The study provides a theoretical basis for the establishment of cooling process after rolling in rebar production.