By using a 13-m loess-paleosol section from the Nula Village, Tacheng in northern Xinjiang, China, the researchers made a series of experiments about magnetic susceptibility, grain size, TOC, CaCO3 of sediments in the section in laboratory. The results show that the grain size distribution is dominated by silty sand (63~4 μm); the magnetic susceptibility is influenced by coarse particle minerals such as the native magnetite mineral, maghemite mineral and hematite mineral and so on, and little magnetic material absorbed by clay sediments and super-paramagnetic minerals generated in soil formation process have been found, so magnetic susceptibility is negatively correlated with fine particles and positively correlated with coarse particles. There is a strong positive correlation between magnetic susceptibility and TOC because of the magnetic effect of biological, chemical cause and effects of self-magnetic in TOC. There is a close relationship between CaCO3 and magnetic susceptibility, and CaCO3 makes great contribution to the magnetic susceptibility in this area.