We studied leaf and twig functional traits, namely, leaf thickness(LTS), leaf area(LA), specific leaf area(SLA), leaf mass(LM), leaf dry matter content(LDMC), leaf tissue density(LTD) and twig length(TSL), twig diameter(TSD), stem wood density(TSWD), leaf intensity(LI), leaf area ratio(LAR), leaf/stem mass ratio(LSMR), Huber value(HV) of Populus euphratica Oliv. in Tarim extremely arid area. We analyzed the variation characteristics of these functional traits along the groundwater depth gradient (GWD), and the trade-off between leaf-twig traits and functional traits combination by One-way ANOVA, Pearson correlation and principal component analysis(PCA), in order to reveal the ecological strategy of P.euphratica to adapt the extremely arid desert environment. The results showed that the variation coefficient was from 8.61% to 59.31%, the HV was the largest (59.31%), LDMC and LAR were the smallest (8.61%, 9.75%) and the most conservative traits. Variance analysis showed that thirteen traits of P.euphratica had significant difference between GWD 1.5m and 4.8m, and there were significant difference of LTS、LTD、TSL、HV between GWD≤2.4m and GWD≥3.5m. Correlation and principal component analysis (PCA) showed that LA, SLA, LDMC, LTS, LTD, LAR, TSWD and HV could be used as important indicators to reflect the characteristics of P.euphratica twig-leaf traits. There were significant correlation between 28 pairs of leaf-twig traits(P<0.05), especially HV was significantly negative correlation with TSL and positive correlation with TSD(P<0.05), and TSL was negative correlation with TSD, as well, HV was significantly negative correlation with LAR, LSMR, LA, LM(P<0.05). Also, leaf display efficiency(LAR,LSMR) were significantly negative correlation with LDMC(P<0.05), and TSWD were negative correlation with LA, SLA. It indicated that there was a potential trade-off mechanism between machine-water safety and carbon availability of P.euphratica in arid areas. P.euphratica adopted the ecological strategy, such as reducing LA, SLA and leaf display efficiency(LAR and LSMR), increasing LTS, LDMC, TSWD and HV, which were beneficial to reducing water loss, storing resources (nutrients and water) and enhancing resilience, to adapt the arid-barren desert environment. Plant economic spectrum also existed in desert ecosystems. With global warming and regional water shortage, it generally shifted towards the conservative strategy of slow investment-return.