1、 There are several possibilities when both parents contribute.
 1. Before marriage, if parents contribute to the purchase of a house for both parties, the contribution shall be deemed as a gift from parents to their children. Regardless of whether the two parties are registered to marry or whose name the house is registered in, the property shall be jointly owned by both children according to their respective share of capital contribution, except for those whose parents explicitly give to both parties.
 2. After marriage, parents contribute to the purchase of a house for both parties. If they are registered in the names of both parties, the contribution will be regarded as a gift to both parties, and both parties jointly own the house, except for those whose parents explicitly give to one party.
 3. After marriage, parents contribute to the purchase of a house for both parties, but if registered in the name of one party, the contribution shall be deemed as a gift from parents to their children, and both parties shall share the house according to their share of contribution.
 2、 If only one parent contributes (assuming that A's parents contribute and the other's spouse is B), there are the following possibilities.
 1. Before marriage, if A's parents contributed but the property was registered in the name of both parties, half of the property rights can be regarded as a gift from A's parents to B. Generally, the property belongs to both parties according to the registration. If A's parents can provide evidence to prove that the gift is conditional on the marriage of both parties, but the conditions for the unregistered marriage of both parties have not been fulfilled, so the contract does not take effect, A's parents can request the return of the property.
 2. Before marriage, if A's parents make contributions and the property is registered in A's name, the property is A's personal property before marriage.
 3. Before marriage, if A's parents contributed but the property was registered in Party B's name, the analysis is the same as
 1. The property can be regarded as a gift from A's parents to B, which is B's personal property. If it can be proved that the gift is conditional, it can be claimed that the contract has not taken effect, and A's parents can request the return of the property.
 4. After marriage, if A's parents contribute and register in the names of both parties, it shall be deemed as a gift from A's parents to both parties, and the property shall be jointly owned by both parties.
 5. After marriage, if A's parents make contributions and the property is registered in A's name, it will be deemed as a gift from his parents to A, and the property is A's personal property before marriage.
 6. After marriage, the property contributed by A's parents but registered in B's name belongs to the property acquired by B during the duration of the marriage relationship, which is jointly owned by the husband and wife, except for those specifically donated to B. In addition, if there is an agreement, it shall be handled according to the agreement.