This paper use the U.S.Environmental Protection Agency's Environmental Health Risk Assessment to evaluate the exposure risk of populations with different ages in three groups of indoor air which meet the quality of Chinese natural standards.The results showed that all the populations living in those environments have non-carcinogenic risk and carcinogenic risk.The population with the age between 0.5 and 10 has the smallest risk among all the populations.Even if the indoor air quality within the standards' range,it still could pose a serious health risk to the human health