Studies of kaolins from Shange with EPR technique indicate that the iron in kaolins exists in two forms: structural Fe3+ ion, which is isomorphously substituted for Al3+ion in the octahedral sheet in kaolinite and free Fe3+ ion, which exists in hematite, limonite and geothite. Structural iron which exists in the octahedral sheet occupies two distinct substitutional sites (I and E). The I iron is due to Fe3+ion at a site having orthorhombic symmetry, and the E iron is due to Fe3+ion at a site of higher symmetry. The structural iron content is 0.081%～0.122% Fe2O3 (I iron 0.031%～0.055%, E iron 0.050%～0.067%). The free iron content is 0.467%～0.648% Fe2O3. It is concluded that the content of I iron and that of E iron are both correlated inversely with the X-ray crystallinity of kaolinite, whereas the ratio of E iron content to I iron content is correlated directly with the degree of order of kaolinite. Chemical bleaching fails to affect structural iron, but can remove most of free iron from kaolin.