A tissue puncturing system used to suture tissues in a body cavity including: an endoscope a flexible sheath having a distal portion provided with at least a side opening and a lumen, through which an endoscope may pass at least one mechanism for puncturing tissue disposed in the flexible sheath, and having a pointed end, which is movable from a first position to a second position and an operation mechanism for moving the mechanism for puncturing between the first and second positions.
