Legal analysis: it does not belong. Buying a house before marriage and repaying the loan together after marriage are not common property. If one spouse buys a house with personal property before marriage and mortgages it, the house is still his personal property and the mortgage loan is his personal debt. After marriage, the participation of one spouse in paying off the loan does not change the nature of the house as personal property.

Legal basis: Civil Code of People's Republic of China (PRC).

Article 1087 Disposal of the joint property of husband and wife at the time of divorce. If the joint property of husband and wife cannot be settled by agreement, the people's court shall make a judgment according to the specific circumstances of the property and the principle of taking care of the rights and interests of children, wives and innocent parties. The rights and interests enjoyed by one spouse in the contracted management of family land are protected according to law.

Article 1089 Joint debts of husband and wife shall be paid off at the time of divorce. If the joint property is insufficient to pay off or the property belongs to each other, and the agreement between the two parties cannot be resolved, the people's court shall make a judgment.