Copper aluminium oxide(CuAlO2) particles, a promissing p-type TCO(transparent conducting oxide), were prepared by spray pyrolysis. Delafossite phase of CuAlO2 was obtained when copper nitrate, copper acetate and copper sulfate, divalent copper precursors, were used as copper precursor and aluminium nitrate as aluminium precursors. However, when copper chloride (CuCl, a monovalent copper precursor) was used, the delafossite phase was not obtained regardless of the type of aluminium precursor. The O2-doped CuAlO2 was obtained by using oxygen as carrier gas.