A dibenzylamine compound represented by the formula (1) wherein R1 and R2 are each a C1-6 alkyl group optionally substituted by halogen atoms and the like; R3, R4 and R5 are each a hydrogen atom, a halogen atom and the like, or R3 and R4 may form, together with carbon atoms bonded thereto, a homocyclic or heterocyclic ring optionally having substituent(s); A is —N(R7) (R8) and the like; ring B is an aryl group or a heterocyclic residue; R6 is a hydrogen atom, a halogen atom, a nitro group, a C1-6 alkyl group and the like; n is an integer of 1 to 3, a prodrug thereof and a pharmaceutically acceptable salt thereof show selective and potent CETP inhibitory activity, and therefore, they can be provided as therapeutic or prophylactic agents for hyperlipidemia or arteriosclerosis and the like.