This invention relates to a highly heat-resistant polyamic acid solution and a polyimide film having improved thermal dimensional stability, wherein the polyamic acid solution includes a polymer of a diamine compound, containing 1 to 10 mol % of a carboxylic acid functional group-containing diamine compound based on the total amount of diamine, and a dianhydride compound, and the polyimide film includes polyimide, which is an imidized product of the polyamic acid solution and is configured such that main chains thereof are crosslinked through an amide bond (—CONH—).