Biological indicators for large river in China are poorly developed.This study evaluates the bioindicators of fish population approach in the upper Dongjiang River and Zengjiang River,which are major source of water for Guangdong Prov.(Guangzhou,Shenzhen and Dongguan city) and Hong Kong region.Xenocypris davidi and Hemibarbus labeo were selected as indicator species.Multiple Factor Analysis was used for estimating expected response to stress of 8 candidate metrics,and then metrics were screened with its stability and responsiveness.Finally,standard length,growth rate,average age and fecundity metrics were selected for X.davidi,and standard length,weight,growth rate,average age,and GSI metrics for H.labeo.Assessment results were obtained by comparing metric values with reference condition.To ensure validity of the assessment results,we compared with the results of human disturbance.The major changes in the river condition,for example,nutrient increased,disturbance caused population decreases or recruitment failed,water pollution,were consistent with environmental changes caused by human disturbance.The validated results showed our method was suitable for assessing the river health of upper Dongjiang River and Zengjiang River.