Abstract: Through the analysis of divorce trend of in China，by using the basic principles of economics，we analyze the relationship between divorce and the diminishing marginal utility，costs and benefits，balance of resource allocation，information asymmetry and utility maximization obstacles. The analysis uncovers，from the angle of economics，the reasons for the increasing number of divorce cases，providing the public with a new angle on divorce，and also a lesson to learn about how to nurture their own marriage.

Key words: marriage, extramarital affair, flash marriage, divorce, economic analysis of divorce reasons