Abstract: It is of significance to understand the controlling effects of urban forest on atmospheric fine particulate matter PM_2.5 pollution. This paper monitored the variations of atmospheric PM_2.5 concentrations in three typical urban recreational forests (Cinnamomum camphora, Pinus elliotii, and Quercus variabilis ) in the Hui Mountain of Wuxi City during the day time (5:00 am-19:00 pm) in autumn and winter, 2011 and in spring and summer, 2012. The meteorological factors were observed simultaneously. The average annual PM_2.5 concentration in the three recreational forests was lower than that above the nearby roads, and this concentration in C. camphora and P. elliotii forests was lower than that in Q. variabilis forest. The average annual PM_2.5 concentration in the forests and above the nearby roads was lower than the background value in the downtown area of the City. The PM_2.5 concentration in the three recreational forests was the lowest in summer, followed by in autumn, and the highest in spring. In addition, the PM_2.5 concentration was the lowest in P. elliotii forest in spring, summer, and winter, and in C. camphora forest in autumn, but relatively higher in Q. variabilis forest in all seasons. The diurnal variation of the PM_2.5 concentration in the three forests in four seasons all showed nearly “one peak and one vale”, with the peak and vale appeared at 7:00-9:00 and 15:00-19:00, respectively. The PM_2.5 concentration was significantly correlated with the air moisture and temperature in four seasons, and significantly correlated with the light intensity in winter. Mild winds throughout the seasons had little effects on the PM_2.5 concentration.