The characteristics of emissions from power plant over Yangtze River Delta were analyzed, and major air pollutants in winter and their impact on air quality were then discussed based on WRF-Chem simulation. The results showed that the annual emissions of major air pollutants from power plant over Yangtze River delta were 826.8Gg, 1475.6Gg and 137.3Gg in 2010 for SO₂, NO_x and PM_2.5, respectively, accounting for 34%, 38% and 14% of total anthropogenic emissions. The high concentrations of major air pollutants (SO₂, NO₂, PM_2.5) were distributed in the city cluster of Nanjing-Shanghai and Hangzhou-Ningbo. The spatial distribution of power plant contribution from SO₂ was consistent with the emissions of SO₂, however, the high contributions of NO₂ and PM_2.5, were mainly distributed on the border of Anhui-Zhejiang-Jiangxi and eastern coast of Zhejiang province. Compared with SO₂ and NO₂, the contributions to PM_2.5 from power plant were relatively low, i.e. normally below 20μg/m³ in most regions (15%). The contributions of power plant emissions to the simulated PM_2.5 and SO₂ during polluted period (6.9%, 34.2%) were higher than clean period (4.9%, 20.7%), while, there were no significant differences for NO₂ between polluted and clean period, with the magnitudes as 10μg/m³. The conditions of low temperature, weak wind speed, and low boundary layer height in winter were not favorable to pollutant diffusion, leading to heavy pollution events.