Surface ecology and hydrothermal distribution are significantly affected by the "corridor-barrier" function in the Red River Basin. This study investigated spatiotemporal trends in the enhanced vegetation index (EVI) and the driving force of its effect from 2000 to 2014 in the Red River Basin. Especially, the response of climatic factors based on the MODIS EVI, combined with the vegetation map, meteorological data, as well as topographic data, were investigated and a trend line and correlation analysis were used. The results showed that:(1) from 2000 to 2014, the Red River Basin EVI showed a declining fluctuating trend, with an annual change rate of -0.15%, with clear spatial heterogeneity. The decreasing area mainly occurred in central Lvchun County and southwest Jinping County, while the increasing area was concentrated in Mojiang County, Wenshan County, the midlands of Malipo, southern Guangnan-Funing County, Yuanjiang-Honghe County, and the southwest of the Tengtiao River. (2) The analysis between the EVI in the growing season and four different time series of climatic factors (monthly mean air temperature and monthly precipitation) showed that the EVI was positively correlated with contemporaneous air temperature. An evident delayed response of EVI to precipitation was observed, accounting for approximately 1 month. (3) Correlation analysis indicated that, in general, EVI was positively correlated with precipitation and negatively correlated with air temperature during the growing season. At the 0.05 level of significance, analysis of the effect of driving factors on EVI showed that about 3.11% of the study area was impacted by climatic driving factors, whereby 1.26%, 0.46% and 1.39% of the area was impacted by air temperature (negative driving effect), precipitation (mainly positive driving effect), and air temperature and precipitation combined, respectively. However, the EVI was affected by non-climatic driving factors in most areas.