The present invention provides a positive resist composition and a resist pattern forming method that are capable of forming a resist pattern with a reduced level of roughness. The positive resist composition includes the compound represented by the general formula (I) below. The present invention also provides the resist pattern forming method using the positive resist composition above. [wherein, in formula (I), R11 and R12 each represents, independently, an alkyl group of 1 to 10 carbon atoms or an aromatic hydrocarbon group, and may include a hetero atom in the structure thereof; R21 to R24 each represents, independently, a hydrogen atom or an acid dissociable, dissolution inhibiting group, and two of the R21 to R24 represents a hydrogen atom and the others represents an acid dissociable, dissolution inhibiting group; X is a group represented by general formulas (Ia) or (Ib) below].