According to a process for hot-dip galvanization of the present invention, a steel sheet is treated by the oxidization/reduction method for better quality of galvanization and then hot-dip galvanized. An annealing line of equipment for hot-dip galvanization is composed of a non-oxidizing zone, an oxidizing zone, and a reducing zone, in his order. A steel sheet containing elements liable to oxidize more easily than iron is oxidized by blowing flames onto it in the oxidizing zone according to the oxidization/reduction method. Further, the steel sheet is reduced and annealed in the reducing zone.