The invention provides a mobile device. The mobile device comprises a motor, a transmission subassembly, a limiting subassembly, two linkage subassemblies and two wheels, wherein the transmission subassembly is linked to the motor; the limiting subassembly includes two limiting plate parts which are disposed in parallel and adjacently; the two linkage subassemblies partially and respectively extend between the two limiting plate parts and are pivotally connected to the two limiting plate parts; the two linkage subassemblies are limited by the two limiting plate parts on a first axis; the two wheels are arranged front and back along a second axis; the two wheels are respectively linked to the transmission subassembly and pivoted to the two linkage subassemblies; the two wheels are respectively driven by the motor through the transmission subassembly and are limited by the first axis through the two linkage subassemblies. In addition, a mobile system including the above mobile device isfurther provided.