Abstract: From the perspective of economics, the women’s sticking to their chastity in ancient China had both cost and benefit. The former can be divided into personal cost, familial cost and social cost. Similarly, the benefit also has three types: personal, familial and social. Through contrast, the author has found that the net profit of sticking to chastity in the feudal society was negative and such act had no beneficiaries. However, in the new time, the net profit of such act is positive and the beneficiaries are chiefly men. And women themselves are also beneficiaries and the act basically has no harm.