A driving system for virtual web camera enabling several applications to access corresponding virtual web cameras is disclosed. The driving system includes the operations of: linking an upper filter to top of USB Video Class Driver as a driver for the virtual web camera through an upper filter driver mechanism provided by an operating system; executing the upper filter to perform initialization and generate device objects, each corresponding to a real web camera as the virtual web camera and having a specific device name; a file handle for the device object being assigned to the application, which opens the device object and then communicates with the web camera without changing the source code; and releasing the file handle when the file handle is closed at the request of the application such that another application can open and use the device object without interfering with other current applications.