Abstract: Characteristics of haze in Ningbo were analyzed using the hourly meteorological data and concentration of pollutants in Zhenhai from 2014 to 2016.The result shows that the hourly frequency of haze is 28.8%,and the ratio of damp haze is 61.0%.The frequency of haze has decreased during the recent three years.Haze occurred more frequently from November to January and less in summer.The diurnal variation of haze has double peaks which appear at 09:00 and 20:00-23:00 respectively.When the haze is heavy,the particulate concentrations of PM_2.5 and PM₁₀ were 2.13 times and 1.92 times as high as those during light haze days.The concentration of particulate matter of dry haze was higher than that of damp haze.The composition of particulate was relatively stable in Ningbo,and the value of PM_2.5/PM₁₀ was around 0.7.The correlation of particle concentration with wind speed and precipitation is good.Wind speed and PM_2.5 is higher in spring and summer,while PM₁₀ is higher in autumn and winter.The correlation between precipitation and PM₁₀ is higher than PM_2.5.The low ground wind speed with stable weather can easily cause an increase in the accumulation of fine particulate matter concentrations.Wind from the northwest and northeast in winter is the main conveying path that results in the change of PM_2.5 concentrations in the Ningbo area.When the wind direction changes to the northwest,PM₁₀ concentration in winter and spring will increase significantly.