The conventional railway vehicle was designed to ensure running stability using high stiffness elements for primary suspensions. Curving performance of the railway vehicle is relatively low because the natural steering motion of a wheelset is constrained by the high stiffness suspensions. High running stability has always been in conflict with good curving performance in conventional design processes. This conflict problem can be solved with an active steering bogie since active elements properly control the wheelset motions according to track conditions such as straight or curved lines. In this paper, an active steering mechanism for railway vehicle is introduced, and the curving performance of the proposed active steering bogie is investigated through simulation and experiments. According to the results, the proposed active steering bogie is highly effective for curve negotiation.