Copper oxide was prepared at 90 ℃ under ambient pressure, with copper nitrate and methenamine as raw materials. The effects of different copper sources( copper chloride,copper acetate and copper sulfate) and solvents with diverse polarity( some solvents obtained by mixing water and ethanol with different volume ratio) on the morphologies of the products were investigated. And the asprepared products were characterized by X-ray diffraction and scanning electron microscopy. The results show that CuO with different morphologies( spherical,fusiform and floriform shapes) can be obtained under different conditions,and both copper sources and polarity of solvents have impacts on morphologies of CuO.