The Qinghai-Tibet Plateau (QTP) is a crucial region for biodiversity conservation and global ecosystem services supply, and its grassland carrying capacity (GCC) is directly related to both herders' livelihoods and the implementation of ecosystem conservation and restoration programs. However, the spatiotemporal distribution of GCC within the QTP and grasslands' responses to future climate change remain unclear. Here, we evaluated the spatiotemporal characteristics of GCC for 60 years and its load during 2000-2020, and then classified levels of early-warning based on whether the grassland is currently overgrazed, and whether the overgrazing is increasing over time. Results showed that (1) GCC increased from 86.15 million to 97.70 million sheep units (SU) during 2000-2020, and GCC was higher in the east than that in the west QTP. (2) Overgrazing was alleviated due to livestock reduction after 2010 and GCC has grown more, but remains serious. The counties with stronger GCC showed more serious overgrazing. (3) Annual mean GCC was projected to increase by 0.05 SU·km