A real-time remote backup system and related method used for a network system connecting at least one source computer system and one destination computer system is disclosed. The system includes a loadable kernel module capable of presetting up at least one specific system call in the kernel space of the source computer system. Besides the kernel software, the specific system call can notify the loadable kernel module to generate a corresponding file modification message when a file modification event occurs in the user space of the source computer system. A scheduling module sequentially queues and implements the file modification messages from the loadable kernel module, and then generates a corresponding backup command according to each said file modification message. And, a network backup unit installed in the source computer system is facilitated to directly back up variant part of the file through the network system to the destination computer system when receiving the backup command transmitted from the scheduling module.