Abstract: 【Objective】 To explore the stability of the fractal characteristics of Tianshan Picea schrenkiana var. tianschanica forest in order to provide new ideas for the zoning investigation of Tianshan spruce forest by taking Picea schrenkiana var. tianschanica forest as the research object. 【Methods】 Taking the Tianshan spruce forest as the research object.Firstly,the worldview-3 image and UAV image were preprocessed by ENVI,PIX4D and other software,and then the fractal dimensions of 171 spruce forest quadrats were calculated by double blanket coverage model method and Fractal Brownian motion method in MATLAB; Finally,the calculation results are analyzed and discussed. 【Results】 (1)The value range of fractal dimension of Picea schrenkiana var. tianschanica forest calculated by the two methods was mainly 2.3-2.6; Under WorldView-3 image,the double blanket coverage model method and Fractal Brownian motion method were used to calculate:the value range of fractal dimension of Picea schrenkiana var. tianschanica forest calculated by the two methods was mainly between 2.2 and 2.7.(2) The value of the fractal dimension of Picea schrenkiana var. tianschanica forest under the two resolution images would not change greatly with the increase of the number of values,and was always in a stable value range. 【Conclusion】 Based on the two methods,the fractal dimensions of Picea schrenkiana var. tianschanica forest under UAV image and worldview-3 image are 2.4513 and 2.4782,respectively. At the same time,its value range of under two different resolutions(0.1and 0.5m) is basically the same,that is,Picea schrenkiana var. tianschanica forest has stable fractal characteristics at a certain resolution.