In order to prepare sources of short-lived actinides for a-particle spectrometry, a coprecipitation method with Sm hydroxide was developed. The preparation procedure can be completed within 5 min with a high chemical yield of over 90%. It was found that the uniformity of the produced sources was sufficient to provide a high resolution of better than 20keV. Under this method, we successfully measured the a-particle spectrum of short-lived Cf isotopes produced in the (238)U((12)C, xn) reaction. (C) 2008 Elsevier Ltd. All rights reserved.