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Global climate change and divergent grassland use systems may lead to divergence and degradation of grassland systems in arid and semi-arid regions. However, the effects of grazing intensity on the gross primary productivity (GPP) of grasslands under climate change and the nomadic versus sedentary grazing systems are still unclear. Here, we investigate the grazing effects on different steppe ecosystems by comparing a ratio index change of nomadic GPP to sedentary GPP (NS) under different grazing intensities. The grassland GPP increased significantly between 2001-2023 across three grazing intensities under nomadic and sedentary grazing systems. The NS index in desert and meadow grasslands increased and then decreased across grazing intensities, with 2012 being the turning point. Surprisingly, the typical grasslands exhibited the opposite characteristics. The impact of differences in grazing systems did not exceed the regulatory role of climatic factors. Random forest analysis revealed that the minimum temperature ratio of the coldest month of nomadic to sedentary sites was the dominant factor influencing the NS index in desert and meadow grasslands. In typical grassland, the precipitation ratio of the warmest quarter of nomadic to sedentary sites is predominantly the NS index. Our study highlights the impact of changing climatic environments on the grassland GPP in the semi-arid region.