The vegetation greening phenomenon usually refers to a statistical increase in annual vegetation greenness index. Researches on large-scale vegetation greening phenomenon, corresponding driving factors and their influence have been widely found. It is still difficult to quantify the contribution of the drivers, especially the research on the impact of land management is still insufficient. In this paper, the northeast agricultural region, which has the most extensive agricultural distribution in China, was selected to analyze the potential contribution of land management to greening through the inter-annual variation and seasonal characteristics of vegetation changes and Enhanced Vegetation Index (EVI) was applied to indicate vegetation condition. During 2000—2019, the interannual trends of EVI over croplands and natural vegetation (forest and grassland) were 2.19×10^-3/a (P < 0.05) and 1.86×10^-3/a (P < 0.05) (1.83×10^-3/a (P < 0.05) and 1.94×10^-3/a (P < 0.05), respectively, that is, at the same magnitude. However, the growth of cropland EVI was mainly concentrated in June to September, with a growth rate of 4.99×10^-3/a (P < 0.05), while the growth rate of natural vegetation was only 2.30×10^-3/a (P < 0.05) (forest and grassland were 1.79×10^-3/a (P < 0.05) and 3.71×10^-3/a (P < 0.05), respectively)at the same time. Climate driving factors are difficult to explain the seasonal asymmetric growth alone. The land management here mainly contains the change of planting type, the use of pesticides and chemical fertilizers and agricultural mechanization. Results demonstrate that the intensity of land management of croplands in this area has changed greatly during 2000—2018. The sowing area of wheat decreases (-85.61%), and that of corn and rice increased significantly by 144.64% and 90.68%, respectively. During the same period, the use of chemical fertilizer and pesticide increased by 112.61% and 80.24%, respectively. The total power of agricultural machinery and the number of large and medium-sized tractors increased by 185.04% and 1192.30% respectively. These land management activities have played a significant role in promoting the growth of crops, which can better explain the higher rate of greening of cropland vegetation compared with natural vegetation during June to September. It is suggested that to further clarify this mechanism, models need to optimize the land management process, and improve the simulation of land management contribution to greening.