By field investigating of reed community characteristics and acquiring monitoring data, we analyzed the bio-ecological characteristics and β-diversity of reed communities in different environmental grads (mainly based on water depth) of Yellow River Delta with methods of multi-analysis, extremum analysis and β-diversity index analysis.ccording square sum of deviations(Ward) cluster analysis, we divide the 10 sampling plots into 6 types, the dominant plants in different plots varied with the changing of environmental gradients. After cluster analysis, it is easily to find that the dominant plants in different types of plots transformed from aquatic plants to xerophytes and salt tolerant plants with the decreasing of water depth.The average height and diameter at breast height of reeds are significantly correlated with average water depth. The fitness curves of reed average density and coverage with average water depth are nonlinear. When average water depth is 0.3m, the average density and coverage of reeds reach apex value. While the height and diameter at breast height of reeds increase with the increasing of water depth.There has obvious change of environmental gradients in Yellow River Delta. Obviously, we found that transitional communities exist in Yellow River Delta by β-diversity analysis. Vicarious species appears with the changing of water depth. The occurrence of substitute species is determined by the function of common species between adjacent belts. The different functions of common species lead to the difference of community structure and function and the difference of dominant plants. The result reflects the difference of species component in different habitats and directly reflects environmental heterogeneity. The values of β-diversity indexes of adjacent plots are higher than that of unadjacent plots. There has transition zone between xerophytes and aquatic plants in Yellow River Delta. In aquatic environment, the similarity of reed community is higher than that of xeromorphic plants. β-diversity index could reflect plant succession trends aroused by the changing of environmental gradients in Yellow River Delta. β-diversity index is important in revealing plant responses to the change of environmental gradient, is helpful to acquire the change patterns of species diversity with the environmental gradient change and the evolving trends in future. It plays an important role when discussing the mechanism of environmental water requirement of wetland.