The Tibetan Plateau has faced environmental degradation in recent years due to intensified human activity and climate change. In this study, the dynamics of net primary production (NPP), annual mean temperature (AMT), annual mean precipitation (AMP), number of animals (NA), number of rural laborers (NRL), and animal husbandry (AH) were analyzed and the response of NPP to climate and human activity explored. The results show that NPP was increasing gradually from northwest to southeast and is similar to the distribution of AMP. In addition, NA, NRL, and AH cluster around Lhasa. Moreover, AMP had a negative correlation with NPP in Tibet while AMT has a positive effect on NPP. Moreover, because of the large number of livestock there is a negative relationship between NA and NPP in most Tibetan regions. Furthermore, it was found that human activity made a higher contribution to NPP in Tibet (24.73%) than climate factors (17.28%). It is, therefore, necessary to further explore the relationship between human activity and the vegetation dynamic in the region.