A flow meter regulation valve fastening structure includes a holder with one side coupled with a regulation valve by screwing. The regulation valve has a regulation shaft with a flange and a screw head located at an upper side. The screw head is coupled with an anchor member. The anchor member has a coupling plate at one end coupled on the screw head and an anchor plate at another end with two detent plates extended downwards from two sides to butt two sides of the frame edge of the holder for retaining. Thereby when the regulation valve is coupled with the holder and a pipe, the junction of the regulation valve and the holder can be prevented from generating fractures due to excessive turning forces.