To understand the effects of relative humidity (RH) and aerosol physicochemical properties on the atmospheric visibility in autumn and winter in northern suburb of Nanjing, the relationships between meteorological elements, particulate matter and visibility were analyzed with the data of meteorological elements, aerosol particle spectra, particulate matter concentration and chemical composition. The average visibility was 4.76 km in autumn and winter in northern suburb of Nanjing. There was a certain negative correlation between the particulate matter concentration and the visibility, especially the influence of fine particles on the visibility was more remarkable. The occurrence frequencies of low visibilities showed an increasing trend with the increasing concentration of fine particles and RH. When the visibility decreased from 5-10 km to <5 km, the mass concentrations of PM10 and PM2.5 increased by 7.56% and 37.64%, respectively. Meanwhile, the mass concentrations of SO4(2-) and NO3-increased significantly. Effects of aerosol particle number concentration on the visibility were related with RH. Aerosol number concentration with diameters ranging from 0.5 microm to 2 microm increased slowly with the increase of RH, while those ranging from 2 microm to 10 microm decreased. The correlation analysis between the aerosol surface area concentration and the visibility showed that RH and fine particles between 0.5 microm and 2 microm were the main factors which caused the decrease of atmospheric visibility in autumn and winter in northern suburb of Nanjing.