Abstract
The lack of explicit rules about preliminary agreements in Iran’s law especially at a time in which there is an urgent need for the existence of various contracts for increasing economical trades causes academia and authorities responsible for civil lawsuits to be confused about reliability and unreliability and /or lawfulness and unlawfulness of preliminary agreements. Therefore, the necessity of providing various reasons and jurists and lawyers’ opinions is clear and it can reveal different aspects of this issue in order to find some solutions for the issues resulted from this entity. In this study, an attempt has been made to reveal legal fundamentals of preliminary agreements after the explanation its concept, Jurisprudential record, and the causes of its development.