Abstract: Non-marital cohabitation has gradually become a more common form of intimate relationship in society. It is a value choice for the law to select some of the de facto cohabitation relationships for evaluation; its legitimacy is based on the equality of legal regulation and the realization of legal values, but the appropriate boundaries should still be grasped with reference to the marital relationship, and demonstrate varying degrees of significance in gender relations, property relations, and parent-child relations. Article 4 of the Interpretation (II) of the Marriage and Family Part has constructed the property division rules in non-marital cohabitation in response to practical needs. In dealing with disputes over the division of property in non-marital cohabitation, the value principles should differ from those of the marital property system and property law, respecting the freedom of will and the protection of the family by the state. In the application of the rules, it is necessary to make a reasonable distinction between disputes over the division of property in cohabitation relationship, disputes over the division of property in divorce and disputes over betrothal property, accurately identify “non-marital cohabitation”, “cohabitation period” and the internal application logic of the rules, and to understand the determination and treatment of debts in non-marital cohabitation from the perspective of systematic interpretation. In addition, the adjudicators can still refer to the application of the rules on compensation for domestic labor in marriage and family based on the litigation request of the parties in disputes over the division of property in non-marital cohabitation.