Contract is invalid, China's contract law stipulates that minors signing the contract is not equivalent to their age to have their legal representative (i.e., the guardian) of the retroactive recognition to be effective, otherwise the validity of the pending. Therefore, the father's claim should be supported by the court.

According to the Contract Law

Article 47, a contract entered into by a person with limited capacity for civil behavior shall be valid if it is ratified by the legal representative; however, a contract for the purpose of obtaining a pure benefit, or a contract that is compatible with the person's age, intellect, or mental state of health, need not be ratified by the legal representative.

The relative may call upon the legal representative to recognize it within one month. If the legal representative fails to do so, he is deemed to have refused to ratify the contract. Before the contract is recognized, the bona fide relative has the right to revoke. The revocation shall be made by notice.