The study of the loess-paleosol sequence of the Lingtai Section in the Loess Plateau,Northwest China,indicates that free iron(Fe_d),active iron(Fe_o)and organic matter contents in the sequence are highly significantly correlated with magnetic susceptibility(χ)(p<0.01).The influence of Fe_d on magnetic susceptibility indicates that the degree of pedogenesis will affect the formation of ferromagnetic minerals in the paleosols.The significant correlation between organic matter and magnetic susceptibility may be attributed to the processes of biogenetic magnet.In addition,the contribution of organic matter to the formation of maghemite in the pedogenetic processes and it interfering with the ageing of maghemite to hematite afterwards are also important reasons.The highly significant correlation between Fe_o and magnetic susceptibility is mainly related to the close relationships between Fe_o and Fe_d,and Fe_o and organic matter.