The disclosure provides a control valve which includes a valve body and a valve gate. The valve gate is movably located inside the inner space. The control valve has a lower flow rate limit which is greater than zero. That is, the lower flow rate limit has no necessary to be zero, thus it is acceptable to have a cylindrical valve gate but not a spherical valve gate. Therefore, the valve gate can be directly installed into the valve body via the opening, which allows the valve body to be made of a single piece so as to simplify the processes of manufacturing and assembly.