This paper introduces a mechanochemical process for synthesizing a nitrate compound, Mg-Al-(NO3) (Mg:Al=3:1), which is a layered double hydroxide (LDH) from three kinds of starting materials, Mg(OH)(2), Al(OH)(3) and Mg(NO3)(2).6H(2)O. The operation was attempted by one-and two-step milling operations, and the former is to grind the three kinds of samples simultaneously, while the latter is to mill two kinds, Mg (OH)(2) and Al(OH)(3), followed by further milling with Mg(NO3)(2).6H(2)O Characterizations by XRD, FT-IR, and TG-DTA indicate that the latter step operation is superior to the former one in terms of the formation of the target material, nitrate form of LDH. This form could be taken as a potential candidate for slow-release fertilizer, where the release of the nitrate from the synthesized LDH has been held back due to the intercalation into the LDH structure. (c) 2007 Elsevier B.V. All rights reserved.