Liquid crystal alignment agent and liquid crystal display unit

The present invention relates to an aligning agent for liquid crystal containing at least a polymer and solvent selected from polyamic acid and polyimide gained by dewatering closed-loop, the solvent contains: (A) a first solvent containing compound with formula (I); (B) a second solvent selected from at least one of N-methyl-2-pyrrolidone, gamma-butyrolactone, 1,3-dimethyl-2-imidazolone, N, N-dimethylformamide and N, N- dimethylacetylamide; and (C) a third solvent selected from at least one of butyl cellosolve, diacetone alcohol, carbonic sub-propyl ester, diethylene glycol diethyl aether and ethyl-3- oxethyl propionic ether. (In formula (I) the R respectively represents alkyl with 3 to 10 carbon atoms).