A computer system and a remote control method thereof are provided. The method is adapted for the computer system having a network and a processor. In the method, the network card is used to receive a management interface request sent by a remote device thorough a network and send a system management interrupt to the processor, so as to wake up the processor and control the processor to enter a system management mode. Then, the processor loads a management monitoring program into a memory so as to execute the management monitor program. Finally, the processor processes the management interface request by using the management monitoring program in the system management mode, and replies a processing result to the remote device through the network by using the network card.