The present invention provides a positive photosensitive resin composition including: a resin containing a specific acrylic acid-based constituent unit capable of undergoing dissociation of an acid-dissociable group to produce a carboxyl group, and a constituent unit having a functional group capable of reacting with the carboxyl group to form a covalent bond, the resin being alkali-insoluble or sparingly alkali-soluble and becoming alkali-soluble when the acid-dissociable group dissociates; and a compound capable of generating an acid upon irradiation with an actinic ray or radiation. The present invention also provides a method for forming a cured film using the composition. The positive photosensitive composition is excellent in the sensitivity, film residual ratio and storage stability and by the method for forming a cured film using the positive photosensitive resin composition, a cured film excellent in the heat resistance, adhesion, transmittance and the like can be provided.