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To adhere to the green growth strategy, it is urgently needed to identify the vegetation degradation zone in the farming-pastoral ecotone (FPE) over the countries along the Belt and Road Initiative (BRI). In this study, we monitored vegetation degradation and analyzed climatic factors and anthropogenic contributions on vegetation change in the FPE during 2000-2016 using the growing season annual accumulative normalized difference vegetation index (NDVIaccu) and climatic variables. The Theil-Sen's trend results revealed that 74.11% of NDVIaccu in FPEs showed a significant increasing trend for the period 2000-2016, only 1.64% of NDVIaccu were significantly decreasing. However, we detected that 21.29% degradation of NDVIaccu had occurred based on enhanced Theil-Sen and Mann-Kendall (ETheil-Sen-MK) method. Spatial statistics for significant correlations between climatic variables and NDVIaccu showed that precipitation was positively correlated with NDVIaccu; yet, the relationship between NDVIaccu and temperature was more complex, which was closely related to the intensity of increasing in temperature. Importantly, this study found that anthropogenic contributions dominated the trends in NDVIaccu over the FPE. The findings suggested that agricultural activities play a mainly positive role in overall vegetation vigor. However, continually increasing disturbance by livestock grazing risks further vegetation degradation.