There are 13 million abortions each year, compared to 20 million births, according to newly published research.
Researchers believe the real figure could be even higher because there are many abortions at unregistered clinics.
China imposed strict family planning rules in the 1970s in an attempt to limit the growth of its population.
Many pregnant women who have had their full quota of children have abortions to prevent unwanted births.
But young single women are most likely to have abortions in a country where there are 20 million births each year, the research found.
Experts said the high number of abortions was “cause for concern”, adding that many women who have abortions are single and aged between 20 and 29.
China began restricting the number of children each couple can have in 1978. Officials say this has prevented 400 million extra births.