Abstract: A lane keeping and following system applied to a vehicle includes a global positioning device, a high-precision road map unit, and a following control device. The global positioning device is used for continuously generating and outputting global positioning information. The high-precision road map unit is used for storing a plurality of pieces of road information. Each piece of road information includes lane information. Each piece of lane information includes lane marking geometric information. The following control device is electrically connected to the global positioning device and the high-precision road map unit, and is used for receiving the global positioning information and matching the road information, to find the lane information currently corresponding to the global positioning information, and retrieving the lane marking geometric information included in the current lane information and controlling the vehicle to travel following the current lane marking geometric information.