It consists of the type of criminology and Criminal Law Science. 其类型可分为犯罪学类型和刑法学类型。
However, in practice, it is also difficult to judge the limits of justifiable defence sometimes.It need further research by experts of criminal jurisprudence gradually. 但是在实践中，有时也很难判定正当防卫的限度，这就需要刑法学专家不断进一步地研究。
