Y(BH(4))(3) was prepared by liquid-phase synthesis, and its dehydriding and rehydriding properties were systematically investigated by performing thermogravimetry and differential thermal analysis (TG-DTA) and powder X-ray diffraction (XRD) measurement. The dehydriding reaction of Y(BH(4))(3) starts at appropriately 460 K, and a total of 7.8 wt% of hydrogen is released up to 773 K. Phase transformation and melting are observed in Y(BH(4))(3) at approximately 474 K and 499 K, respectively. Both DTA and XRD measurement results indicate that the decomposition of Y(BH(4))(3) proceeds via multistep dehydriding reactions accompanied with the formation of an inter-mediate phase. Furthermore, Y(BH(4))(3) is proved to be partially rehydrided. (C) 2009 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.