My wife spent $10000 on our wedding. Does she can demand that money at the time of divorce? If yes what I need to do?

She can ask for anything, but getting it is another story. You should consult with an experienced CA attorney, only a CA attorney can provide you with specific legal advice. Use 's Find a Lawyer tool to select a qualified attorney. Good luck.

Why would she demand the money back that she spent on the wedding? Spending money on a wedding does not create the existence of a community or separate property asset or debt. "what I need to do?" - you need to hire a lawyer to assist you with your divorce.

You did not mention how long you have been married. It would be interesting to know. In a standard divorce proceeding, there is no legal theory under which one spouse can demand back the costs of the wedding. If she is claiming you married her under fraudulent pretenses (e.g. to get a green card) and she is seeking to have the marriage declared void, then she could make an argument that she relied on your fraudulent misrepresentation and should be reimbursed. Given the expense of litigating such an issue vs. the $10,000 in question, it seems unlikely.