Soluble Poly(propargyl benzoate) (PPBT) with p -conjugated structure was synthesized using a novel bis(triphenylphosphine)-bisacetylide palladium complex catalyst [Pd(PPh3)2(Co CCH2OOCPh)2] (PPB). An interdigital gold electrode was covered by screen printing films of doped PPBT (DPPBT) to prepare a resistance-type humidity sensor, which exhibits electrical response towards relative humidity (RH%) variations in the range 11%-96%. PPBT shows promise as a new humidity-sensitive material.