The alpine tundra ecosystem has a sensitive response to global climate change, and widespread studies of continuous upward invasion of herbaceous plants had been reported. The upward invasion of herbaceous plants is characterized by stages and spatial variation. Recently, Veratrum oxysepalum was observed to expand rapidly in the tundra of Changbai Mountain, becoming the dominant upward invasive species. The original dominant species, shrub plant Rhododendron aureum communities, and soil fertility in the tundra, also change synchronously. The study of the impact of the upward invasion process of Veratrum oxysepalum on native shrub plants and soil fertility is significant to demonstrate the response of tundra ecosystem to global climate change. This study continuously monitored the biomass of Veratrum oxysepalum and Rhododendron aureum communities, and measured soil fertility in different upward invasion degrees of Veratrum oxysepalum from 2017 to 2019; Using the spatial instead of temporal method, reveals the differences of herb and shrub plants communities' biomass, along with soil total and available nutrients supplies at different stages of upward invasion by Veratrum oxysepalum. The results indicate that, with the upward degree of invasion of Veratrum oxysepalum increased, the biomass of Rhododendron aureum decreased continuously, and the content of soil organic matter (SOM) and total nitrogen (TN) decreased continuously. In contrast, soil available nitrogen (AN) and available phosphorus (AP) contents increased. However, different changing trends in the biomass of Rhododendron aureum and soil fertility under different degrees of Veratrum oxysepalum upward invasion emerged: from none upward to mild upward invasion stage, the changes of Veratrum oxysepalum and Rhododendron aureum biomass were the fastest, with the soil fertility changes were also the most significant; As the degree of upward invasion of Veratrum oxysepalum increased, the rate of biomass change of Veratrum oxysepalum and Rhododendron aureum slowed down, and the amplitude of soil fertility change also decreased. When the invasion stage reached the severe upward invasion stage, the rate of biomass change of Veratrum oxysepalum and Rhododendron aureum is the smallest, and the amplitude of soil fertility change is also the smallest. There is a high correlation among the biomass of Veratrum oxysepalum and Rhododendron aureum, and soil fertility. With the continuous changes in the environment of the tundra zone, there may be a transition from positive to negative feedback between the upward invasion of Veratrum oxysepalum and changes in soil fertility. The upward invasion rate of Veratrum oxysepalum is inhibited, and the plant community structure and soil fertility tend to stabilize.