Plentiful and systemic research work about existence form of cadmium in soil and its effect factors have been studied according to topsoil samples, deep-seated soil samples and modality samples obtained in zoology geochemical survey work from Liaohe River Basin of Liaoning Province. And the result indicates that main existence form of cadmium in soil from Liaohe River Basin is ion exchange form, water-soluble form, ferrimanganic oxidative form, carbonate binding form, organic binding form, humic acid binding form and residual form. Ion exchange form and water-soluble form could be absorbed and utilized by microbes, and its content depends on conditionality factors such as content of cadmium in soil, pH value, organic content and viscosity of soil etc.