We report that decomposition pathway of Ca(BH4)(2) can be efficiently controlled by reaction temperature. That is, it decomposes into CaB6 at a lower temperature range of 320 to 350 degrees C, but into amorphous boron at 400 to 450 degrees C. We identified the formation of CaB2H6 as the crucial intermediate step on the way to CaB6 that only forms at 320 to 350 degrees C.