Precontract has been existed for a long time in society. Majority of countries build the precontract system with legal mechanism, but the writer of this article tries to reconstruct precontract system with nonlegal mechanism. Chapter1teases out the legal theory of precontract, including differences between precontract and related notions, legal characters of precontract, validity of a precontract, doctrinal classifications of precontract and typical precontract. Despite the majority of countries build preco...