Abstract: Data of particulate mass concentration,including black carbon (BC),PM_2.5 and PM₁₀,were analyzed together with surface meteorological factors in Suzhou,China,from September 2009 to May 2010.We conducted correlation analysis between visibility and particulate mass concentration,as well as meteorological elements including relative humidity,wind speed,wind direction and air temperature.The results indicated that visibility was negatively correlated with mass concentration of BC,PM_2.5 and PM₁₀,with correlation coefficients of -0.465,-0.359 and -0.238,respectively.Under low relative humidity (≤60%) conditions,the correlation coefficients were -0.675,-0.411 and -0.364,respectively.The correlation coefficients between visibility and air temperature,wind velocity and relative humidity were 0.132,0.188 and -0.632,respectively.A linear regression model based on BC,PM₁₀ and relative humidity was built,though the result was not good enough.Based on the linear model,we built a more complicated regression model,in which the multiple correlation coefficient was 0.865 and the coefficient of determination was 0.749.