A clipping instrument for an endoscope is provided. The clipping instrument includes a flexible sheath and at least one clip assembly with a pair of openable and closable clipping arms. The clip assembly is arranged in vicinity to a distal end portion of the flexible sheath with the clipping arms closed. The clipping arms are configured to be protruded forward to open outside the flexible sheath and to be closed to clip onto a treatment object outside the flexible sheath. The clipping instrument further includes an operating wire, which is configured to be forwarded and retracted to operate the pair of arms to be opened and closed. The clip assembly includes a bendable portion, which corresponds to a position of a shaft to support the clipping arms. The clip assembly can be arbitrarily bended at the bendable portion.