The subject is the function of the rule of sahlah and samhah in criminalization. Since the crime is abnormal and against values, it has always followed the punishment which is society's reaction. The effectiveness of the criminal system against such a phenomenon depends on the rules governing that system. The main reason for the stability of any criminal system is its governing rules. The rule of sahlah and samhah plays a fundamental role in the foundation and continuity of the criminal system in all phases of criminal policy, including the criminalization phase. At this stage, the legislator, taking into account the norms and basic values of the society and relying on his accepted theoretical foundations, prohibits the current act or omission and imposes a criminal executive guarantee for it; It should take into account ease and flexibility, otherwise criminalization will be temporary. According to this, the rule of sahlah and samhah is to make criminalization flexible, in all eras and among all nations, the same result of the ease and tolerance of the rule leads to the decriminalization and rejection of the charge of total authoritarianism from criminalization, which in this descriptive and analytical research, Baroush It has been obtained through the resources available in the libraries and facilities.