Magnetic properties can be simply,rapidly and accurately measured,and their pedogenetic implications are significant.In this study,63 soil samples collected from 11 subgrade soil profiles distributed in the downtown area of Nanjing were tested for low-frequency susceptibility,frequency dependent susceptibility,free iron oxide,active iron oxide,particle size distribution,organic carbon,pH and calcium carbonate equivalents.Results show that magnetic mineral and soil-forming processes were highly diversified due to heterogeneity of parent materials and artificial input.Magnetic minerals were mainly derived from fly ash,automobile exhaust and so on High pH and carbonate content retarded formation of fine magnetic minerals in urban en vironment.Magnetic susceptibility combined with other pedogenetic properties is very useful in illustrating the soil-forming processes in urban areas.