The invention relates to a liquid crystal aligning agent, a liquid crystal aligning film and a liquid crystal display element, wherein the storage stability of the long-term low-temperature storage of substrates is good and the coating property of substrate is excellent. The liquid crystal aligning agent provided by the invention comprises a polymer (A) selected from at least one out of groups formed by polyamic acid, polyimide and polyamide acid ester obtained through the reaction of tetracarboxylic acid dianhydride with diamine, with the presence of specific diamine; and a specific solvent (B).