China ranked 13th on a list ranking international health conditions released by a Chinese Academy of Sciences (CAS) study group yesterday.

The tally uses a Nation Health Index (NHI) combining four branch indexes measuring populations' metabolisms, immunities, nervous systems and behavior, and determined China to be "qualified healthy".

"A nation is like a person," CAS' study group leader Yang Duogui said. Yang explained that immunities hinge on ecological conditions, resistance to financial risk and social stability.