Abstract: A clamp-type corrugated plastic pipe coupling of the invention, which is clamped with a split mold having flanges, includes an outer coupling member having a corrugation at least on its inner surface and a packing member arranged inside the outer coupling member. The packing member has an inner surface with a corrugation substantially identical to the corrugations on outer surfaces of corruated plastic pipes to be connected. The packing member is made of a material having a rubber hardness of not more than 25 and a compression set of not more than 60%. The corrugated plastic pipe coupling having the above structure has watertightness which can sufficiently withstand a water pressure of 5 kg/cm.sup.2 or more even when it is subjected to heat cycles between -25.degree. and 80.degree. C.