This paper focused on six species of common herbaceous plants in Yanhe River Basin,including Heteropappus altaicus,Artemisia sacrorum,Artemisia giraldii,Stipa bungeana,Bothriochloa ischcemum, Stipagrandis.Ten investigated plant functional traits were specific leaf area (SLA),leaf tissue density(LTD),specific root length(SRL),root tissue density(RTD),leaf nitrogen concentration(LNC), leaf phosphorus concentration(LPC),leaf nitrogen phosphorus ratio(LNP),root nitrogen concentration (RNC),root phosphorus concentration(RPC)and root nitrogen phosphorus ratio(RNP).These 10 plant functional traits were chosen because they were easily measured and adequately reflected plant survival strategies. Combining with the data of plant genetic background and environmental factors,we analyzed the sources of plant functional traits variation.The results showed that:(1)under different climatic conditions, in addition to LTD,other functional traits presented the significant differences;SLA,LNC,LPC,RNC and RNP of Asteraceae were significantly higher than those of Poaceae,SRL was significantly lower than that of Poaceae;(2)plant species and climate changes were the main sources of variation,the ranking importance of 8 plant traits variation sources was in the order:species>annual precipitation>annual evaporation>annual temperature>slope>slope position>elevation>aspect;(3)according to different genetic backgrounds and environmental tolerances,different species regulate the expression of traits and produce the corresponding survival strategies to adapt to environmental changes.