Abstract: Grassland, is one of the most widespread vegetation types in the world, and accounts for nearly 20% of the global land surface. China has abundant grassland resources, and the second largest grassland area of any country. However, in recent years, China’s grassland ecosystem has suffered dramatic impairment through human activities and climate change. Grassland in the Heihe River Basin provides necessary resources for the livelihood of local communities. It is therefore important to monitor grassland change. In this study, we assessed historical grassland cover in Heihe River Basin using GIS technology and evaluated land use and land cover change (LUCC) since 1986. We also predicted the future grassland distribution pattern using a CA-Markov Model and land-use transfer matrix, reflecting change in spatial distribution and metabolic indices of grassland. In 1986, the total area of grassland in the Heihe River Basin was 32998 km², of which 4290 km² were classed as having high coverage, 6372 km² were classed as having medium coverage and 22336 km² were classed as having low coverage. In 2000, the grassland area was 23939 km², and areas with high, medium and low coverage were, respectively, 5509, 5540 and 12891 km². In 2011, the grassland area was 24273 km², and areas with high medium and low coverage were, respectively, 5561, 5715 and 12996 km². During the period 1986-2000, the area of grassland in the Heihe River Basin was considerably reduced and severe degeneration occurred. During this period, there was substantial transformation of grassland from high to medium coverage, from medium to low coverage, and from low coverage to unutilized land. During the period 2000-2011, the grassland area in Heihe River Basin increased slightly and transition between the three coverage classes was small. Finally, in 2022 the predicted grassland area of the Heihe River Basin is 24450 km² with, respectively, 5560, 5658 and 13232 km² with high, medium, and low coverage, respectively.