根据塔里木河下游英苏至喀尔达依区段距离河流50～300 m的80个胡杨(Populus euphratica)一级枝生物量实测数据，采用数理统计方法构建胡杨一级枝和树冠生物量估测模型，在精度检验基础上筛选出最佳模型，并对其估测值与实测值进行卡方检验。结果表明：使用以胡杨一级枝条的基部直径（D）和枝条长度(L)派生因子D2L为自变量估测生物量(Sb)的模型Sb=125.546(D2L)0.654最优，使用以冠幅面积(A)为自变量估测树冠生物量(Sc)的模型Sc=0.016A2+2.291A+11.084最优，在离河300 m内，两模型平均估测精度分别为93.75%和87.01%;在离河600～1 500 m进行估测时需根据修正因子进行修正，修正后平均估测精度分别为86.04%和84.32%。根据全收获法得到的胡杨树干平均材积密度(748.43 kg·m-3)和样地每木检尺数据，使用树干材积计算式和树冠生物量估测模型，计算胡杨平均标准木的树干和树冠生物量，从而得到样地胡杨地上生物量数据。这一研究将为塔里木河流域胡杨生物量的遥感估测和胡杨林碳汇功能研究提供直接依据。

Mathematical statistics methods were applied to establish the biomass estimation models of first-class branch and canopy of Populus euphratica. Eighty first-class branches data  were collected in the sampling plots which were distributed 500-300 m distance to the river in Yingsu and Ka'erdayi section in the lower reaches of Tarim River.The best estimation models for each of them were picked out based on accuracy test, and then the significance of the difference between estimated value and measured value was tested according to Chi-square way. It was found that the equation model, Sb=125.546(D2L)0.654 (Sb, D and L refer to biomass, base diameter and length of first-class branch, respectively), which by using D2L as parameter was best to estimate the biomass of first-class branch, while the best equation model used to estimate canopy biomass was Sc=0.016A2+2.291A+11.084(Sc, and A refer to biomass and area of canopy, respectively), in which canopy area was used as parameter. Both of them can be applied to estimate the biomass within 300 m distance to the river, the accuracy of them was 93.75% and 87.01% respectively, but both of them must be modified when used in the range of 600 m to 1 500 m distance to the river, and the accuracy of them was 86.04% and 84.32% respectively after modified. According to the data of stem volume density (748.43 kg\5m-3) acquired (by harvest method and every tree measured in each square, to calculate the biomass of stem and crown of P. euphratica by using biomass estimation models, subsequently, the total aboveground biomass of P. euphratica was acquired. This study can provide direct evidence for the RS estimation of biomass and carbon storage study of P. euphratica in the reaches of Tarim River.