Birds not only serve as indicator species for urban environment changes but also act as a medium to promote public engagement in the protection and improvement of urban ecological environment. In-depth understanding of the relationship between urban bird diversity and landscape characteristics is of great significance for conserving biodiversity in cities and promoting urban sustainable development. In this study, 436 recorded bird reports from the main urban area of Fuzhou in 2020 were collected from the Chinese Birdwatching Network website to calculate the bird richness index (S), Shannon-Wiener diversity index (H), and Simpson diversity index (D). A total of 15 landscape factors were quantified using Google Earth Engine and high-resolution Worldview (0.5 m x 0.5 m) imagery. Differences in S, H, and D were examined between two grid scales (300 m and 1000 m) using the Mann-Whitney U test. A generalized linear model was applied to explore the dominant landscape factors and their significance in influencing three bird diversity indices at two scales. The results revealed the following:(1) in 2020, a total of 242 bird species were observed by the public in the study area, belonging to 19 orders and 59 families, with Passeriformes being the dominant species. The proportion of each category, in descending order, was as follows:resident birds (63.53%), winter visitors (25.83%), migratory birds (6.71%), and summer visitors (3.93%). (2) There were substantial differences in bird diversity indices between the two scales, with significantly higher values observed for both S and H indices at the 1000 m scale compared to the 300 m scale (P < 0.1). (3) The significant landscape factors influencing bird diversity were identified exclusively at the 1000 m scale (P<0.05). The proportion of urban road area (RD) and building height (HT) exhibited negative effects, while the proportion of urban green space (GA) and building volume (BV) demonstrated positive effects on the bird diversity indices. Notably, GA was the only factor that positively influenced all three diversity indices. These urban landscape characteristics, representing both two-dimensional and three-dimensional structural features, played significant role in shaping urban bird species diversity. The findings suggest that the relationship between urban bird diversity and landscape factors exhibits a noticeable scale dependency. The use of a 1000 m grid scale is highly likely to be more suitable for investigating such associations. The ecological benefits of preserving expansive green spaces and promoting a compact urban structure in cities deserve significant attention.