The material authority of the military and law enforcement forces has various tools. The most obvious example of this severity of action is the use of weapons to maintain order and security in society. The authorities and responsibility of using weapons by officers is of fundamental importance since it is associated with the security of the political system on the one hand and the citizenship rights of the members of the society on the other hand, and investigating it in the laws of Iran and another country helps to explain the issue as much as possible. The present paper is descriptive and analytical and investigates the mentioned subject using the library method. The findings indicate that both in Iranian law and in British law, officers have the authority to use weapons in defined conditions and cases. These cases are more extensive in Iranian law than in British law. The right to legitimate defense, the necessity and the use of weapons as a last resort is one of the common aspects of the use of weapons in the laws of the two countries. The civil responsibility of officers is also accepted in the laws of the two countries. There is this difference that the injured party has the right to go to the police and the relevant authorities for compensation, which is limited in Iranian law, and in British law, it is possible to claim damages in cases such as psychological injury. Also, the criminal responsibility of officers in the use of weapons has been accepted in both countries, and in case of violation of the prescribed conditions, it will be followed by the punishment determined by the law in each specific case.