A polarizing plate protective film containing an acrylic resin, in which the acrylic resin includes a methyl methacrylate unit a, a mass fraction of an alkyl (meth)acrylate unit b other than methyl methacrylate is less than 5 mass %, a weight average molecular weight is 250,000 to 4,000,000, and a weight decreasing amount at the time of being heated at 140° C. for 1 hour is less than or equal to 0.5%, has excellent heat resistance and an excellent surface shape; a dope composition; a method for manufacturing a polarizing plate protective film; a polarizing plate; and a liquid crystal display device.