The perovskite-type oxide catalyst LaMnO3 prepared by the sol-gel method was found to be an efficient heterogeneous and recyclable catalyst for the wet aerobic oxidation of lignin to aromatic aldehydes. The lignin conversion rate and the yield of each aromatic aldehyde were enhanced significantly by the catalytic process as compared with the non-catalyzed process. Moreover, the activity, specific surface area and perovskite-type structure of the LaMnO3 catalyst remained nearly unchanged after five successive recycles of catalytic reactions.