As private power is increasingly valued, it is increasingly common for husbands and wives to establish each other's rights and obligations in a contractual manner. Most of these agreements have common characteristics, that is, the right to identity and property are closely integrated, and often belong to property interests As the final legal consequence of the agreement, modern marriages have become so fragile, and the Shanmeng oath has made people feel insecure, and people are more inclined to maintain the security of marriages in a contractual manner to protect their property rights after the marriage breaks down. This passage mainly talks about the contract between couples in marriage:. ['Appearance.', 'Conditions of existence.', 'Main functions.', 'Legal effect.']