a b s t r a c t a r t i c l e i n f oHydrodeoxygenation of eugenol to hydrocarbons in aqueous phase can be catalyzed by the combination of Pd/C and HZSM-5. In this paper, micro-, submicro-and nano-sized HZSM-5 samples were chosen as catalysts to investigate the influence of crystal size of HZSM-5 on the hydrolysis and dehydration. It was found that the formation rates of hydrocarbons were correlated with the total acidic sites of the submicro-and nano-sized HZSM-5 samples; while for the micro-sized sample, a much lower hydrocarbon formation rate was observed. Meanwhile, HZSM-5 with larger crystal size showed a lower hydrocarbon formation rate even with higher acid density.