An operation control system for a work apparatus equipped to a work vehicle includes a controller controlling the work apparatus. A first hydraulic valve and a second hydraulic valve control hydraulic pressure supply to the work apparatus. An operation unit provides an operation input signal to the controller. A first mounting base and a second mounting base are provided adjacently to each other in the operation unit. A first single-operation tool is formed mountable on the first mounting base and a second single-operation tool is formed mountable on the second mounting base. Further, a multi-operation tool is mountable so as to straddle both the first mounting base and the second mounting base.