The marriage procedure between Mexicans and China people.

First of all, you should be very sure whether they will get married in China or Mexico, because the things to be prepared are different. If they get married in Mexico, they must go back to the marriage registration department in Mexico for inspection. But if you get married in China, you should go to the civil affairs bureau where your sister's household registration belongs to make an appointment to register for marriage.

Information to be submitted:

Your sister:

1. My household registration book and resident ID card.

2. A signed statement that I have no spouse and have no direct blood relationship with the other party and collateral blood relationship within three generations (the statement is provided by the marriage registration authority).

Your brother-in-law:

1, my valid passport or other valid international travel documents.

2. A certificate issued by the notary office or competent authority of the host country and certified by the people of China and the embassy (consulate) of China in that country or the embassy (consulate) of China in that country that I have no spouse; Or a certificate from the embassy (consulate) of the host country that I have no spouse. Relevant certificates issued by countries that have not established diplomatic relations with China shall be certified by the embassies (consulates) of third countries that have established diplomatic relations with that country and China and the embassies (consulates) of China in third countries, or by the embassies (consulates) of third countries in China. The declaration or certificate of no spouse in Hongkong, Macau, Taiwan Province Province and abroad shall be valid for 6 months from the date of issuance.

After marriage, the nationalities of both parties will not change. Unless they apply for naturalization through marriage, their respective nationalities will not be affected. You don't have to worry about that. Of course, if both parties want to live in each other's place without changing their household registration, they must apply for a visit visa, and the time they can stay depends on relevant laws and regulations. In this regard, you should consult the Exit-Entry Administration. Even if your sister applies for Mexican citizenship, she can still stay in China. But as for the length of stay, it depends on Mexico's immigration law.