To analyze causes and characteristics of a wide range haze in January 2013 in China, mass concentrations, size distribution and spatio-temporal variation of atmospheric particles in eight major cities were investigated, as well as correlations were analysed between haze and meteorological factors, principal component and correlation analysis also were investigated that of atmospheric pollution indicators in eight major cities during haze period. Results showed that mass concentrations of fine particles(PM2.5) exceeded standard by 234% on average, with most serious from 11th to 14th, the mean ratio of PM2.5/PM10 is 0.72. In addition, meteorological conditions with high humidity, thermal inversion, low pressure and calm wind are in favor of formation of haze. Strong correlations are found between PM2.5 and SO2 as well as NO2, principal component analysis indicated that combined pollution existed in many cities. The haze of wide range in January 2013 in China was caused by vehicle exhaust and coal fume combined pollution which additionally dominated by specifical meteorological conditions.