A resist composition, which comprises: (A) a resin containing a repeating unit represented by formula (I); and (B) a compound capable of generating an acid upon irradiation with actinic rays or radiation: wherein AR represents a benzene ring or a naphthalene ring; R represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group; Z represents a linking group for forming a ring together with AR; and A represents an atom or group selected from the group consisting of a hydrogen atom, an alkyl group, a halogen atom, a cyano group and an alkyloxycarbonyl group, and a pattern forming method using the resist composition.