Damage reduction is one of the important rules in compensation, according to which the injured party has the duty to take any conventional action necessary to reduce the damage and prevent the development of the damage. It will not have damages. This rule has not been discussed in the Germanic Roman system, which Iran belongs to, but its effects and results can be applied and implemented in the laws of these countries. The desired approach can be applied in private law issues. In this regard, this article is written under the title of the necessity of damage reduction and the basics of the injured party's obligation to perform it in Iranian law with descriptive analytical method and library sources, and its findings are indicative of this. that regardless of the result of the actions taken by the injured party in order to reduce the damage, the injured party should act in a normal manner and even if his action causes an increase in the loss, it does not affect the amount of compensation he is entitled to claim, and based on jurisprudential principles, Like the rule of caution, harmlessness, action, as well as verifying the relationship of causation and foreseeability of the loss, and if there are conditions for applying the rule of liability for damages, including breach of contractual obligation, the possibility of reducing the damage, informing the injured party of the breach of obligation, etc. ..the victim is obliged to reduce the damage according to Iran's laws.