State media says applications for DNA tests in one major city hospital have risen 20% over the past year.
Other clinics in Beijing have reported significant increases.
Doctors say the situation reflects the instability of family relationships as more people lose confidence in the loyalty of marriage.
“It reflects that family relationships are unstable and shows the low level of trust between husbands and wives,” Xiao said, a hospital administrator.
“With the increase in one-night stands, disloyalty within a marriage, relationships become vulnerable and people lose confidence of the loyalty of marriage,” the doctor was quoted as saying.
China News Service said there had already been 200 tests at the city hospital by mid-September and there would have been many more if the cost were not so high.