A precursor derived from (HAIN(i)Pr)(m) and [MeSi(H)NH](n), which mainly consisted of cage-type compounds and cyclic compounds, respectively, was converted into Al-Si-N-C ceramic composites via pyrolysis. A dehydrocoupling reaction between AlH groups and NH groups occurred at low temperatures (less than or equal tosimilar to250degreesC), which mainly accounts for its high ceramic yield (69% up to 900degreesC). At high temperatures (greater than or equal tosimilar to250degreesC), the organic groups were decomposed. The product pyrolyzed at 1350degrees and 1500degreesC under Ar contained a 2H wurtzite-type compound and a beta-Si3N4-type compound, while beta-SiC was clearly detected in addition to these compounds in the product pyrolyzed at 1600degreesC under Ar. On the other hand, the product pyrolyzed at 800degreesC under NH3 and subsequently at 1350degreesC under N-2 consisted of AIN and beta-Sialon.