Provided is an in-plane-switching liquid-crystal display element having superior burn-in properties and to which an orientation control ability has been imparted at a high efficiency. The present invention achieves same by means of a polymer composition containing (A) a photosensitive side-chain polymer that expresses liquid-crystal properties in a predetermined temperature range, (B) at least one type of polymer selected from the group consisting of a polyimide and a precursor thereof, and (C) an organic solvent. In particular, the present invention achieves same by means of a method that is for producing a substrate having a liquid-crystal orientation film and obtains a liquid-crystal orientation film for an in-plane-switching liquid-crystal display element, to which an orientation control ability has been imparted, by means of having: [I] a step for forming a coating film by applying the polymer composition onto a substrate having a conductive film for in-plane-switching; [II] a step for radiating polarized ultraviolet rays at the coating film obtained in step [I]; and [III] a step for heating the coating film obtained in step [II].