Abstract:Wetland is a unique ecosystem formed by the interaction of land and water, but due to the impact of climate change and human activities in recent years, it has shown a certain degree of degradation. Wetland have become one of the most threatened ecosystems. The degradation of wetland is also the degradation of plants and soil. Therefore, this paper chooses the wetland of the first meander of the Yellow River was selected as the research object. Based on field sampling data and different degradation degrees of wetland (Non Degradation, ND; Light Degradation, LD; Moderate Degradation, MD; Heavy Degradation, HD) to analyze the characteristics of plant community and soil and their relationships. The results of this study showed that the important value of Gramineae plants decreased with the increase of the first meander of the Yellow River degradation. Nevertheless, the importance value of noxious weeds increased with the increasing degree of the first meander of the Yellow River degradation. At the same time, it was found that plant height, coverage and aboveground biomass decreased significantly with the increase of wetland degradation degrees. The Patrick species richness index was the lowest in the severe degradation of wetland in the first meander of the Yellow River, which indicated that the plant community structure of wetland changed from complex to simple to some extent. Soil organic carbon and total nitrogen decreased significantly with the increase of wetland degradation, while the ratio of carbon to nitrogen and pH value showed the opposite trend. The result indicated that the increase of alpine wetland degradation was not conducive to the accumulation of soil nutrient content, and the soil gradually became alkaline. This study found that soil pH, soil organic carbon and total nitrogen were physicochemical factors in response to alpine wetland degradation. Soil factors affecting plant community characteristics were slightly different in different wetland degradation degrees, among which soil electrical conductivity had the most obvious effect on plant community characteristics, which was related to soil nutrient content at that time. In the degradation process of wetland in the first meander of the Yellow River, the growth and structural characteristics of plant community have changed obviously, and the physical and chemical properties of soil and their interaction with plant community have changed, thus affecting the ecological function of wetland. Therefore, the study of plant community and soil physical and chemical characteristics can provide a basis for restoring the degraded wetlands.