This study was a preliminary examination on the interactions between chemical characteristics of oily soil and detergency of particulate soil in oily/particulate mixed soil system, which enable to understand the detergent process of particulate soil in interfacial chemical aspect. The dispersion stability of particle increased with oily soil in colloidal dispersion, and decreased with increasing amount of oily soil and decreasing surfactant concentration, but the influence of polarity of oily soil on dispersion stability was low. And emulsification power of polar oily soil was higher than those of nonpolar oily soil, and increased with decreasing amount of oily soil and increasing surfactant concentration. This results showed that chemical characteristics of oily soil such as polarity effect of oily soil exerts on emulsification power than the dispersion stability. But the trend of dispersion stability of particle are similar to emulsification power of oily soil.