Abstract: In order to study the legal consequence of operating outside business scope by company,this paper first analyses the nature of company' s business scope and points out that it is the company's particular civil right capacity.Then,this paper studies the evolution of relevant laws with historical method.Finally,combining with legal theory of contract force and obeying the thought of distinction between private and public laws,this paper concludes that the force of contract outside business scope should be judged from the contract itself.The theory of non-relevance can be proved true by solving real problems.