An avian soundscape is the soundscape in which bird vocalizations constitute the dominant biophonic component, interacting with geophony and anthrophony within a specifi c spatiotemporal context. It serves as a vital indicator for assessing ecosystem integrity, community dynamics, and biodiversity. Grounded in the Acoustic Niche Hypothesis and the Acoustic Adaptation Hypothesis, research in this fi eld bridges landscape ecology, ethology, and urban planning, which has recently emerged as a focal area for elucidating the mechanisms by which birds adapt to both natural environments and anthropogenic disturbances. Employing a systematic review, this article analyzes literature published between 2005 and 2025 to examine theoretical advancements and practical applications of avian soundscapes in urban green remnants and nature reserves. Bibliometric and keyword co-occurrence analyses reveal: (1) A signifi cant upward trend in publication volume. International research has followed a clear trajectory, shifting from an early focus on assessing the negative impacts of anthropogenic noise to the use of acoustic indices and machine learning for biodiversity quantifi cation and monitoring. Conversely, domestic research in China, though emerging later (commencing in 2011), places greater emphasis on soundscapes and their restorative eff ects on human health. (2) Regarding research frontiers, the integration of Passive Acoustic Monitoring (PAM) with deep learning has become the mainstream approach. This synergy enables the automated processing of large-scale acoustic datasets, thereby significantly enhancing the effi ciency of species identifi cation and ecological and behavioral analyses. (3) Regarding practical application, the avian soundscape has emerged as a vital resource for landscape architecture. We analyze the feasibility of transforming scientifi c data into immersive landscape experiences through case studies of the Cornell Lab of Ornithology and the Huanglong National Scenic Area. We suggest that avian soundscape research in urban green remnants and nature reserves is characterized by distinct theoretical emphases and applied research orientations. Future research should further disentangle the spatiotemporal heterogeneity of avian soundscapes across environmental gradients and develop prediction models based on acoustic monitoring data. Furthermore, landscape design practices must address the ecological paradox between human recreational needs and acoustic disturbance to wildlife, aiming to balance ecological conservation and human well-being.