Tamarix chinensis is an endemic species in the Yellow River Basin, and a key species in maintaining fragile habitats in this region. The quantification of the interspecific affinity and structural diversity of T. chinensis community was the premise and critical to explaining the interaction mechanism between the community and environment for the transitional vegetation zones of the Yellow River Basin. Each individual of the T. tamarix community was located and surveyed in the transitional floodplain wetland of the lower Yellow River. Using R, the interspecies association index, niche width, α diversity index, spatial structure parameters, etc., were calculated to analyze the interspecific affinity, niche characteristics, species and structure diversity. The results showed that the overall community showed a non-significantly positive association (VR=1.25), with T. chinensis exhibiting strong associations with Cyperus iria, Potentilla supina, and Eclipta prostrata. The ratio of positive to negative correlations was 0.5, with T. chinensis showing positive correlation with P. supina (r=0.30). T. chinensis had the largest niche width (23.32), but owned the higher niche overlap with C. iria (0.696) and P. supina (0.675), while only weak competition existed among the remaining 66.7% of species pairs. Species diversity and evenness were low, with limited size variation and differentiation among seedlings. The community exhibited slightly aggregated distribution, moderate advantage state, poor mixing, and low crowding, indicating weak spatial heterogeneity (FSS=0.301) and diversity (FSD=0.352). These findings suggest that the overall community was unstable. The interspecific associations among most species pairs were weak, showing a trend of weak collaboration and low competition, and the diversity of stand structure was poor. As a constructive species, T. chinensis demonstrated strong adaptability but faced intense competition from C. iria and P. supina. This study provides important insights into interspecific interactions and structural characteristics of T. chinensis seedling communities in transitional Yellow River floodplain wetland, offering a valuable theoretical basis and technical references for vegetation biodiversity conservation and ecology restoration in the lower Yellow River wetlands.