Provided are a radiation-sensitive composition including a compound (P) having a partial structure (A) having an ionic structural site and capable of decomposing upon irradiation with an actinic ray or radiation to generate an acid and a partial structure (B) having at least one phenolic hydroxyl group, a part or all of hydrogen atoms of the hydroxyl group or groups each being protected by a group capable of leaving by the action of an acid, wherein the ionic structural site of the partial structure (A) contained in the compound (P) is a structure capable of generating an acid anion in the compound (P) upon irradiation with an actinic ray or radiation; a pattern-forming method using the same; and a resin which is used in the composition.