New co-polyhydrazides, which contain spacer groups consisting of carbohydrates, methylene groups or aromatic moieties and also having pendant groups were synthesized by low temperature solution polycondensation of diacid dihydrazides with diacid dichlorides in DMF (Scheme 1). One example of the prepared co-polyhydrazides was cyclized into copoly(1,3,4-oxadiazole); which was treated with ammonia for de-O-acetylation to give de-O-acetylated carbohydrate containing co-polyhydrazide (Scheme 2). Structural identification as well as solubility and thermal properties of the various copolymers are presented. (c) 2005 Elsevier B.V. All rights reserved.