Abstract: In order to understand the growth and distribution of the natural Cupressus chengiana forest in the upper reaches of Dadu River,the cypress forest were chosen as the object in Maerkang and Jinchuan counties.Taking high definition remote sensing image as the bottom map,the ground survey and ARCGIS vectorization technology were used to investigate the habitat factors of agrotype,slope,slope direction,elevation accessibility and DBH,tree height in different habitats.The results showed that 1) 85.64% of the agrotype was bare rock and highly gravel stone.Small,medium and large diameter groups were mainly distributed on gravel stone,bare rock and soil.2) The trees could grow on different slopes,and the area of north,northwest and west occupied 68.04% of the total area.These three slope directions were the concentrated distribution areas of cypress,with large area,high height and small diameter tree species.3) The trees mostly grew on steep slopes,60.33% of which were above 36°.Different diameter groups and tree height were concentrated on steep slopes,and dangerous slopes.4) The trees mainly grew at the altitude of 2 301 m~2 500 m,and the distribution area accounted for 81.01% of the total area.Along with the growth of trees,the altitude distribution of cypress was decreasing.5) Due to the influence of river partition and steep slope,the accessibility of trees was pretty low,and 83.27% of the area was unreachable.