Affected by social institutional transformation and climate change, Kazakhstan is the most significant country with ecological degradation and grass-livestock contradiction in Central Asia. Over the past century, the distinct characteristics of various grassland ecosystems have changed due to agricultural reclamation, changes in grazing patterns, and climate change in Kazakhstan. Therefore, it is important to study the process and mechanisms of grassland degradation in Kazakhstan in order to understand the responses of grassland ecosystems to climate change and human activities in Central Asia. These findings may also support regional ecological sustainable development in the construction of green silk roads. Ecological change research is based on the land cover statistics. However, there are significant differences between the current widely-used global data sets, leading to uncertainty in the understanding of ecological variation and the simulation of future change. This study compared the similarities and differences of grassland distribution using five types of global land cover data (UMD 1992-1993, MCD12Q1 2001, GLC 2000, CCI-LC 2000, Glob Cover 2005). Grassland type identification, consistency of spatial distribution and the cause of spatial distribution variation were used to provide the basis for selection of land cover datasets in Kazakhstan. Results showed that: ① the primary cause of differences in grassland definitions were differing remote sensing data sources, ancillary data, classification methods, verification methods, and data within the five data sets. The MCD12Q1 data had the largest difference in grassland distribution area; ② the area of grassland distribution overlaps within the five data sets (complete consistency) or within the four data sets (high consistency) accounted for only 39.66% of the total, which were mainly located in the typical grassland and part of the semi-desert grassland. The spatial consistency gradually decreased from the inside to the outside around the typical grassland distribution zone. An inconsistent zone within the five data sets accounted for 26.78%, mainly located in the desert grassland; ③ CCI-LC2000 data had the highest areas of overlap compared to other types of data. There were 76% of the grassland overlapped with areas of complete consistency or high consistency in the five data sets. In the inconsistent areas, the most easily confused land cover types were mainly rainfed cropland, irrigated cropland, mosaic cropland and natural vegetation, bare areas and shrub land.