Abstract: Highly electrically conductive and stable macrocyclic poly-conjugated systems are provided from a preferred polymer comprising a repetition of cyclic structures each represented by Formula (1): ##STR1## X and Y each are at least one group selected from the group consisting of a C--C unsaturated bonding group, a C--N unsaturated bonding group, an N--N unsaturated bonding group, an Si--Si bonding group and at least one group selected from the group consisting of an aromatic ring, a heterocyclic ring and their derivatives. .alpha., .beta., .gamma., and .delta., when they do not form a closed ring with X, are each at least one group selected from the group consisting of a hydrogen atom, a C.sub.1-5 lower alkyl group, an --NH.sub.2 group, and an --NR.sub.2 group in which R is a C.sub.1-5 lower alkyl group. When .alpha., .beta., .gamma., and .delta. form a closed ring with X, (.alpha. and .beta.) or (.gamma. and .delta.) together jointly represent ##STR2## in which R is a C.sub.1-5 lower alkyl group.