Abstract: Spatial distribution pattern of Populus euphratica and P. pruinosa clonal ramets at three sites was studied, including natural mixed forest of P. euphratica and P. pruinosa in Awati County located in the downstream of Yarkant River, natural P. pruinosa forest in Group 16 of Nongyishi in the Tarim River upstream area, and natural P. euphratica forest in Luntai County located in the middle reach of the Tarim River. The clonal ramets of the three sites showed a cluster distribution pattern at eight sampling scales, i.e., 5 m×5 m, 5 m×10 m, 5 m×15 m, 10 m×10 m, 10 m×15 m, 15 m×15 m, 15 m×20 m, and 20 m×20 m. This pattern revealed that the cluster distribution was a basic property in the spatial distribution pattern of P. euphratica and P. pruinosa populations. At 5 m×5 m scale, negative binomial parameter  was minimum, while Cassie index, patchiness index  and aggregation strength were maximum for the two ramet populations at the three sites.