Abstract: A mobile machine, a braking system of a mobile machine and a method of controlling a mobile machine. The mobile machine (1) comprises a movable carrier (3) and several wheels (4). The mobile machine is driven (D) on a work site by means of a hydrostatic drive system. The machine is stopped by means of operating brakes. Driving and stationary state of the machine are detected by means of sensing devices (14, 15, 21, 23a, 23b, 24). When the machine is stationary, parking brake devices (28) are activated automatically.