A number of biosimilars will be soon marketing due to the expiration of patent protection of their originators.Unlike classical chemical drugs,biotherapeutics are proteins with large and complex molecules produced by biological high-tech with sophisticated manufactural procedures.This leads to the difficulties of the copy of biosimilars from their originators,and the almost inevitable distinctions between the two products.Thus biosimilars are only similar but not identical to their reference drugs in terms of stracture,action,and safety.It is important for physicians to understand these differences before using biosimilars.Optimal management by a national regulatory authority with rigorous standards is very important in all aspects of authorization of the development,production,marketing,and postmarketing surveillances for biosimilars.