Abstract: A clamping device (1) for connection in which a housing (4) rotatably accommodates a worm screw (5) to mesh with an array of teeth portion (6) of a strap band (3). The strap band (3) is diametrically contracted upon operating the worm screw (5) to wind the strap band (3) around a connecting portion (2). One end portion of the strap band (3) in which the array of teeth portion (6) resides, is formed into a wavy and concavo-convex configuration in its width direction, thus increasing a meshing area of the array of teeth portion (6) against the worm screw (5). This makes it possible for the strap band (3) to cope with a situation in which the strap band (3) is required to tightly wind the connecting portion (2) with a high tightening force.