A liquid crystal alignment agent which is capable of forming a liquid crystal alignment film with excellent ultraviolet reliability, the liquid crystal alignment film, and a liquid crystal display element having the same are provided. The liquid crystal alignment agent includes a polymer composition (A) and a solvent (B). The polymer composition (A) is obtained by reacting a mixture, wherein the mixture includes a tetracarboxylic dianhydride component (a) and a diamine component (b). The tetracarboxylic dianhydride component (a) includes a tetracarboxylic dianhydride compound (a-1) represented by formula (1). The diamine component (b) includes a diamine compound (b-1) represented by formula (2) and a diamine compound (b-2) containing the structure represented by formula (3).