The ferroelectric properties were studied for polyamides consisting of m-xylylenediamine (MXD) and aliphatic dicarboxylic acids with the number of carbon atoms n=6 to 11, which were designated as nylon MXDn. Quenched samples of these polyamides exhibited the ferroelectric hysteresis loop with the remanent polarization P r of 25-67 mCm-2 which decreased with increasing n. Strip-biaxial and biaxial drawing of nylon MXD6 caused the preferential orientation of molecular chains parallel to the direction of drawing and to the film surface, respectively, and increased the value of P r. A reversible pyroelectric coefficient of 4 to 12 µC·m-2·K-1 was observed for nylons MXD6 and MXD7. The polarization was depolarized with increasing temperature and vanished at the glass transition temperature of the respective samples. The ferroelectricity of nylon MXDn is related to the amide groups aligned by the electric field in amorphous regions.