A motherboard sliding mechanism adapted for removing a motherboard out from a housing of an electronic device includes a bracket, a connecting member, and a sliding assembly. The bracket includes a supporting board and a sidewall perpendicularly extending from an edge of the supporting board, the supporting board defines a guiding groove. The connecting member slidably passes through the guiding groove, and is capable of detachably fixing the bracket to the housing of the electronic device. The sliding assembly is rotatably assembled on the bracket and detachably connected to the connecting member. The sliding assembly is capable of being rotated to lock or unlock the connecting member to drive the connecting member lock or unlock with the bracket, and the motherboard sliding mechanism with the motherboard can be conveniently slid out of the housing of the electronic device or firmly fixed in the housing of the electronic device.