Calcium borohydride hydrazinates, Ca(BH4)(2)-nN(2)H(4) (n = 4/3, 1, 2, 3) have been synthesized successfully. In particular, Ca(BH4)(2)center dot 2N(2)H(4) crystallizes in a monoclinic space group of C2/m with the lattice parameters of a = 10.1385 angstrom, b = 8.6342 angstrom, c = 4.6384 angstrom, beta= 106.467 degrees. It can release 5.9 equiv. gas/Ca(BH4)(2) (approximately 8.8 wt. % H-2) at 240 degrees C. Ca(BH4)(2)-N2H4 and Ca(BH4)(2)-4/3N(2)H(4), on the other hand, show superior dehydrogenation properties under the same condition, i.e., around 9.2 wt.% and 10.8 wt.% hydrogen can be released from these two samples, respectively. It is suggested that two dehydrogenation pathways, i.e., direct combination of H delta--H delta+ and ammonia-intermediated mechanisms, are likely to be involved in the process of dehydrogenation. Furthermore, the dehydrogenation temperature can be reduced significantly from 240 degrees C to 140 degrees C by introducing a Fe-based catalyst. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.