The present invention relates to a system and a method of predicting traffic speed based on the speeds of neighboring links. A system for predicting traffic speed on a link basis, on a map based on a past traffic patterns, includes a prediction model establishment unit that establishes a neighboring link speed-based prediction model including the correlation between the speed of each link and the speeds of neighboring links based on real-time traffic information accumulated in a real-time traffic information database for a predetermined time, a prediction model database that stores the established neighboring link speed-based prediction model data, and a traffic speed prediction unit that inputs real-time neighboring link speed information for a specific object link to the neighboring link speed-based prediction model and predicts an output value according to the real-time neighboring link speed information as the traffic speed of the object link.