AbstractThe electric properties of polymer composites with highly conductive 7,7,8,8‐tetracyanoquinodimethan (TCNQ) salts such as quinolinium–TCNQ complex salt (), acridinium–TCNQ complex salt (), andN‐methylacridinium–TCNQ complex salt () were studied. Polyacrylonitrile (PAN), poly(N‐vinylcarbazole) (PVK), and poly(4‐vinylpyridine), (P4VP), etc., were chosen as matrix polymers. The resistivity (ρ) of the was 0.37 Ω cm at the content of 20 wt % in the film. When the content of was increased up to 40 wt%, a phase separation of the needle crystals was observed and the ρ value increased. When was dispersed into PAN or PVK, the separation was also observed and the samples showed low conductivity. The uniform films were obtained in the and systems, but the values of ρ were high because of the degradation of the TCNQ salts. Uniform films with the naked eye were obtained in the and systems, and the values of Ω were 0.37, 1.05, and 3.40 Ω cm, respectively. was stable even when dispersed into P4VP. The properties of the composites were influenced by the combination of the TCNQ salts and the polymers. The uniformity and the stability of the composites were necessary to obtain the high co