With naphthalene as a model compound, catalytic cracking experiments on biomass tar were made on Ni-dolomite catalysts. The performance of catalyst preparation, activity, coke formation and regeneration were analysed. The results showed that the ratio of the one-step conversion of naphthalene was 95% at space velocity 0.81 h(-1) and 700 degrees C; with saturated wet air as regeneration gas, the regeneration time was within 0.5 h; compared with thermal cracking at the same reaction temperature, the catalytic cracking was propitious to deep cracking of naphthalene. (c) 2004 Elsevier Ltd. All rights reserved.