In an apparatus for controlling operation of a utility vehicle that detects a magnetic field generated during flow of electric current through a boundary wire laid around a working area and is driven to run within the working area based on the detected magnetic field, having left and right magnetic sensor installed at lateral right and left positions of the vehicle to produce outputs proportional to strength of the magnetic field, turning mode is switched between a gentle turning mode to make the vehicle turn while running near the boundary wire and a sharp turning mode to make the vehicle pause near the boundary wire and then turn, when it is determined from the outputs of the magnetic sensors that the vehicle approaches the boundary wire, each time predetermined conditions are satisfied, and operation of the prime mover is controlled such that the vehicle turns in accordance with the switched turning mode (S10 - S36, S100 - S142, S200 - S218).
