The involvement of criminal law in establishing order in any society is essential. However, excessive intervention has led to criminal inflation, and this causes the judicial system of the country to face important problems, including a negative impact on judicial justice. The purpose of this article is to investigate the causes of legal criminal inflation in Iran and the challenges arising from it.The research method is descriptive and analytical and this research is theoretical. The method that has been used to collect information is in the form of a library and it has been done by referring to books and articles.Lack of a coherent criminal policy, multiplicity of legislative authorities, lack of attention to customs and collective conscience, mixing of the border between wrongdoing and crime, unfavorable economic conditions, extreme criminalization and traditional approach in criminalization are the most important causes of legislative criminal inflation in Iran. Prohibition of the role of the country's legislative authorities, other than the Islamic Council, from legislating in the criminal field, increasing the technical and technical burden of the Islamic Council in establishing criminal rules, paying attention to the important principles of criminalization such as the principle of necessity, paying attention to social conscience in criminalization, Paying special attention to social prevention and applying a set of decriminalization policies in different dimensions are the basic solutions to face the challenges caused by criminal inflation.