The spatial distribution and correlation of population is an important means to study population diffusion, community succession and the interaction between biological and environmental factors. The study takes Reaumuria songarica and Stipa sareptana var. krylovii as the main species in Laohutai arid desert area of Gaolan County, Gansu Province. The spatial distribution characteristics and their association of R. songarica and S. sareptana var. krylovii on different slopes were analyzed by using Ripleys k function, revealing the competitive relationship, survival, and reproduction strategies among dominant populations in the process of plant succession in arid desert areas. The results showed that: (1) there were significant differences in the distribution of R. songarica and S. sareptana var. krylovii in the four slopes. With the change of slope aspect from northwest to south, the plant number, coverage and important value of R. songarica population increased first and then decreased, while the population of S. sareptana var. krylovii increased continuously. In the northwest slope, the R. songarica population showed aggregation distribution on the scale of 0-2.1 m, with the increase of the scale, the aggregation intensity weakened and tended to random distribution, and the population of S. sareptana var. krylovii was mainly aggregation distribution; In the west slope, the R. songarica population showed random distribution on the whole scale, and the S. sareptana var. krylovii population showed aggregate distribution; In the southwest slope, the population of R. songarica showed aggregation distribution on the scale of 0-3.7 m and random distribution on the scale of 3.7-5 m, the S. sareptana var. krylovii population showed a random distribution on the scale of 0-1 m and 4.2-5 m, an aggregate distribution on the scale of 1-4.2 m; In the south slope, the R. songarica population showed aggregate distribution on the whole scale, and the S. sareptana var. krylovii population showed random distribution. (2) In the northwest slope and west slope, the R. songarica and the S. sareptana var. krylovii showed negative correlation on the small scale, with the increase of the scale, the interspecific correlation of the species tended to be unrelated; In the southwestern and southern slopes, the two species showed no correlation in the whole scale.