Potassium titanate (K 4 Ti 3 O 8 ) was synthesized by the reaction between ilmenite and concentrated KOH solution in the atmosphere of nitrogen, still air, and oxygen, respectively. The obtained samples were systematically investigated by X-ray diffraction (XRD), inductively coupled plasma optical emission spectrometer (ICP-OES), and scanning electron microscopy (SEM). XRD results indicate that K 4 Ti 3 O 8 have been synthesized in different atmospheres. The oxidizing atmosphere could enhance the conversion rate of Ti from ilmenite to K 4 Ti 3 O 8 , and Fe(II) is easily oxidized to trivalent iron Fe(III) during the reaction. Furthermore, SEM images show that the different atmospheres have significant effect on K 4 Ti 3 O 8 crystal morphology and particle size. Well shaped K 4 Ti 3 O 8 crystals are obtained in nonoxidizing atmosphere.