The response of grassland soil bacterial community characteristics to different grazing intensities are central ecological topics. However, the underlying mechanisms between bacterial abundance, diversity index, and grazing intensity remain unclear. We measured alpine meadow soil bacterial gene richness and diversity index under four grazing intensities using 16S rDNA sequence analysis on the Tibetan Plateau. The results suggest that extreme grazing significantly decreased alpine meadow both bacterial gene abundance and diversity index (P<0.05). The lowest operational taxonomic unit numbers were 3012 ± 447 copies under heavy grazing in the growing season. It was significantly lower than heavy grazing with approximately 3958 ± 119 copies (P<0.05). The Shannon index for medium and high grazing grassland bacterial diversity was slightly higher than for light grazing in the growing season. Furthermore, the lowest index was approximately 9.20 ± 0.50 for extreme grazing of grassland in the growing season. The average bacterial gene abundance and diversity index in the dormancy period was slightly higher than that in the growing season. Soil bulk density, pH, ammonium and nitrate nitrogen were the main positive factors driving grazed grassland bacterial communities. Our study provides insight into the response of alpine meadows to grazing intensity, demonstrating that moderate grazing increases bacterial community diversity in grazed grasslands.