A recording material comprising a substrate and a polyguanidine salt of the general formula (1) contained in said substrate: wherein R1 and R2 may be the same or different, and each represents a group selected from the group consisting of a divalent aliphatic hydrocarbon group, a divalent aromatic hydrocarbon group and a divalent alicyclic hydrocarbon group; HX is an acid selected from the group consisting of a mineral acid and an organic acid; and p is an integer of 1 to 250.