The aim of this research was to compare the effectiveness of harm reduction programs on reduce crimes of addicts inside the Drop In Center (DIC) in Karaj city. The sample of 120 people was selected randomly for study in this center; the ones referri ng DIC have been examined through informative questionnaires. The statistical population includes people was chosen through random sampling method. In the next step, the subjects assigned in two groups, first group was as an experimental group including 60 subjects that measured the effective of independent variable (harm reduction intervention) and the second also consisted 60 subjects, as a control group. Data wags analysis using Chisqu are (P