The informal logic development in the past thirty years has been closely integrated with the actual practice of argument, and has developed into a new logic tool different from formal deductive logic. The theories of argument analysis, argument evaluation, argument criticism and construction established by informal logic have the strong tendency to be the general logic universally applicable to all the fields. The theoretical achievements derived from Toulmins “jurisprudential model” can be applied to legal argument, and have formed a totally new logic of legal application.