Abstract: A method and reinforcing materials are developed for repairing underground water pipeline without excavation. The reinforcing materials, which have forcibly rolled to form a cylindrical shape is inserted into the pipeline. Then, it will be expanded to tightly seal the damaged or cracked inner wall areas of the pipeline. A series of guiding belts are employed for circumferentially mounting on the outer surface of the reinforcing materials to form a sleeve. Thus, it is smoothly inserted into the water pipeline by pulling one end. Once the sleeve is inserted into the pipeline, the sleeve is steadily expanded to seal and tighten the damaged area. Accordingly, the repair work is easily facilitated to seal the damaged area of the pipeline without excavation. The repair materials have formed as a simple sleeve with smooth inner surface for minimizing the finishing process, such as a cutting. Thereby, the leakage is efficiency prevented without disconnecting the water supply.