The present invention is to provide a polyamide-imide which has a high regularity of molecular structure and few branched structures, does not contain hydrogen halide, is not required to be separated and purified in post processes, and can be suitably used as a film, a varnish, or a molding material; raw material salt of polyamide-imide and production method thereof.The polyamide-imide has a repeating unit represented by the general formula (1): in which R1, R2 represent independently a divalent residue having an aromatic ring, an aliphatic ring or an aliphatic hydrocarbon; R3, R4 represent independently a trivalent residue having an aromatic ring or an aliphatic ring; and an hydrogen atom bonding to the respective rings may be replaced by another atom or an atomic group.