Global urbanization has increasingly led to the simplification of riparian vegetation structures and the weakening of their ecological functions. As an integral component of urban green infrastructure, riparian vegetation assumes a crucial role in ecological restoration. However, existing research has predominantly concentrated on single climate zones or localized urban case studies, thus lacking systematic cross-climatic and cross-governance comparisons. This comparative literature review adopts the framework of Nature-based Solutions (NbS) to examine Perth, with its Mediterranean climate, and Beijing, characterized by its temperate monsoon climate, as representative cases. Based on their contrasting climatic conditions and management regimes, this study systematically compares the horizontal, vertical, and temporal structures of riparian vegetation in the two cities and analyzes their ecological strategies, to reveal the mechanisms underlying their climate–management–ecology interactions. The study endeavors to elucidate the structural differences in riparian vegetation across differing climatic zones and to propose adaptive optimization strategies. Furthermore, it provides theoretical guidance for enhancing ecological resilience and functional integration within diverse urban contexts. Grounded in the NbS framework, the findings contribute to a more profound understanding of riparian ecosystems and offer practical insights for urban riparian ecological restoration on a global scale.