The governing body of gymnastics says athletes will now have to carry a passport-type identification at major championships to ensure they are eligible to compete.
At last year's Beijing Olympics some media reports suggested the gold medal-winning Chinese women's team included three underaged competitors.
Athletes must be at least 16 during an Olympic year to compete at the Games.
The Gymnastics Federation investigated the matter and was satisfied with evidence provided by the Chinese authorities.
It says it hopes the new requirements will deter competitors from trying to fake their ages.