Aluminum borate (9Al2O3·2B2O3) whiskers were chemically synthesized in potassium sulphate flux by using the starting chemicals of aluminum sulphate and boric acid. The synthesis temperature of 1075 °C was found to be the optimum with respect to whisker morphology. A tentative X-ray diffraction (XRD) pattern was suggested for the whiskers produced after heating at 1150 °C. The product purity, phase composition, and whisker morphology were investigated by XRD, energy dispersive X-ray spectroscopy, and scanning electron microscopy, respectively.