Abstract: Surface modification was carried out on hot dipping aluminizing surface of Q235 steel by argon arc remelting technology.The preand post microstructure steel treated by the argon arc remelting was investigated using SEM and XRD, the preand post microhardness of specimen cross section by argon arc remelting was also determined.Effect of argon arc remelting parameters on microstructure and mechanical properties of hot dipping aluminizing surface was investigated.The results show that, for the hot dipping aluminizing coating after argon arc remelting treatment, stratification phenomenon disappeared, gradient transition on microstructure appeared, specimen consisted of remelting layer, transition layer and substrate.Argon arc remelting treatment can obviously increase microhardness of hot dipping aluminizing coating.The process parameters influence the depth, hardness and crack rate of the remelting layer markedly.With the welding current increasing or the welding speed decreasing, the remelting layer depth and hardness increases, and the crack rate decreases.