Abstract：Chemical characteristics of aerosols in summer were studied during June of 2013 in Xianghe observation station of the Chinese academy of sciences. Mass concentrations of PM2.5 and PM10 were recorded by online measurement. The result showed mass concentrations of PM2.5 and PM10 were (151.78±82.48) μg/m3and (250.47±106.99) μg/m3with average and standard deviation. SNA (SO42-, NO3-, NH4+) accounted for 44.8% of PM2.5, and it mainly enriched in the particles which size range from 0.5 to 2.5 micrometers. The average of SOR and NOR were 0.35, 0.31, respectively. The transformation method of SO2 into SO42- was heterogeneous reaction, and NOx transformed into NO3- was mainly by photochemical reaction during the daytime. The high value of SOR and NOR during haze and mist indicated that there is more SO2 and NOx into SO42- and NO3- in haze and mist favor transformation of sulfur and nitrogen, rather than in clear day. The backward trajectories analysis showed air quality in haze and mist were influenced by air masses mainly passing through Hebei, Shandong, and the north of Jiangsu Province.