Abstract: Bird diversity is an important indicator for biodiversity assessment and ecological environmental impact assessment. The researches on bird diversity in China have been abundant in recent years; however, the impact of bird diversity on biodiversity is equivocal. In this study, the reasons for fluctuations on bird diversity components in Liaoning Province were investigated. Birds were counted twice around 6 sites during the breeding season for 8 consecutive years. A total of 10 fixed sample lines with a length of 3 km and 23 fixed sample points were set up. Through 8-year study, 202 622 birds of 178 species were recorded, belonging to 50 families, 17 orders. The dominant species and most common species were mainly waterbirds. 70 species were summer migrants, 47 were travelers and 47 were residents. A total of 3 first-class and 16 second-class of national protected birds were recorded. Among the 6 studied sites, 4 diversity parameters of Laotuding showed the smallest fluctuations, while Liaohekou and Huanzidong had relatively large diversity fluctuations. In general, bird diversity in woodland is relatively stable, while the wetland bird species diversity fluctuates probably due to the rapid destruction and reconstruction of related habitat.