Today, the overcrowding of prison populations has caused serious problems in all societies so that in many ways undermined the correctional and educational achievements. In many countries of the world, the overcrowding population of prisoners has brought nothing except huge costs, an impediment to the public order of the prison, conflict, riot, strike, etc. It has made the authorities to take steps to reduce the prison population. The prison sentence for any form of criminal behavior that is determined arbitrarily neither based on scientific logic nor on the basis of the personality characteristics of individuals and entities of society, on the one hand, causes the increase of the prison population and represents an ugly face of the Islamic Republic of Iran to the world and, on the other hand, causes the family of prisoners to be wandered and overwhelmed by the effects and consequences of this punishment. It is impossible to deny the prison functions because it has punitive and corrective functions so that multiple objectives can be achieved by its implementation. Therefore, it cannot be ignored totally. Imprisonment is still considered as a solution, and if it turns to be a problem in some cases, it is due to other factors and conditions that need to be addressed and improved. If imprisonment is used logically, then it will be effective and will certainly not be problematic. In particular, it should be emphasized that non-criminal solutions and imprisonment alternatives will be effective when it is used in place. Accordingly, the penal policy in post-revolutionary penal law has contributed to the increased prison population by imposing ineffective and prison-based laws in the general section, and also by increasing the criminalization and determination imprisonment as the dominant type of punishment in the section of general laws defining punishment with increasing crime However, following the problems and corruptions as well as the need for resolving this challenge, the legislature took steps to change its legislative penal policy through the Islamic Penal Code of 2013 in accordance with the inspirations and solutions of international organizations. It resulted in the reduction of imprisonment and consideration of prison as the last punishment.
