The average age gap between Shanghai women and their foreign husbands is 10.5, and 13 percent of the foreign husbands are 20 years older than their local brides, the report said.

However, divorces in foreigner-involved marriages also reached 355 last year, the report said, claiming it to be a "significant increase" without giving a comparison.

Some locals regard the marriage as a chance to become rich or go abroad, which causes the divorce, said Shu Xin, a member of the Committee of Marriage and Family Affairs.

Some Shanghai women marry foreigners without considering the entire situation, and when they reach foreign countries, they feel depressed because reality is far from their expectations, Shu said.