Change in vegetation coverage, which can reflect the direction of regional succession in ecosystems, is the result of the combined action of meteorological factors and human activities. As an important water conservation and recharge area in the upper reaches of the Yellow River, the alpine ecological zone of Maqu County plays an important role in maintaining regional biodiversity and ecological security, and also in ensuring the healthy development of human economy and society. Clarification of the relationships among vegetation change and climatic conditions and human activities or other environmental factors in this region would thus make an important contribution to ecological management and restoration in Maqu County. Therefore, we used trend, correlation, and path analyses to analyze the temporal and spatial variation of vegetation normalized difference vegetation index (NDVI) in Maqu County based on MODIS/NDVI data obtained between 2000 and 2015 and meteorological and human activity data for the same period. Furthermore, we present a detailed discussion on the effect of meteorological factors and human activities on vegetation cover change. The following results were obtained. (1) Fluctuation in the NDVI of Maqu County increased from 2000 to 2015, with a rate of increase of 0.01015/10 a. Among all land use and cover types, the range increased in the following order:alpine sparse vegetation > wetland > desertification meadow > open forest > alpine meadow > subalpine sclerophyllous shrubs > subalpine broadleaf shrubs > alpine grassland. The order of the increasing area accounting for the total area was alpine sparse vegetation (75.57%) > open forest (71.45%) > desertification meadow (71.18%) > wetland (70.66%) > alpine meadow (68.15%) > subalpine sclerophyllous shrubs (66.96%) > subalpine broadleaf shrubs (66.24%) > alpine grassland (66.05%). (2) Among the meteorological factors examined, there was a significant positive correlation between temperature and NDVI (P < 0.05), which was a decisive factor affecting vegetation cover and beneficial to the growth and development of vegetation. Vegetation cover was less affected by precipitation and there was no significant correlation between precipitation and NDVI (P > 0.05). (3) Among the human activities examined, large livestock and sheep population numbers were the main factors controlling vegetation growth, which was closely related to grazing intensity, with large livestock populations having significant inhibitory effects (P < 0.05) and sheep populations having strong promoting effects (P < 0.05). (4) Path analysis yielded decision coefficients of 0.3005, -0.0563, and 0.0128 for air temperature, large livestock population number, and sheep population number, respectively, indicating that the effect of temperature on NDVI was the strongest and the effect of sheep population number was the weakest. In addition, the residual path coefficient of 0.53 indicated that there are certain other environmental factors that have an effect on the increase of NDVI, but were not taken into consideration, which warrant further attention in future research.