A linear guideway includes a rail, a sliding block with two foot members, a circulating member with two receiving chambers, two sets of balls and two lubricating plates. The receiving chambers of the circulating member receive the foot members of the sliding block respectively, so that the rail, each foot member of the sliding block and the circulating member form a circulation channel for one respective set of balls to run. The two lubricating plates are adjacent to the two circulation channels and contact the two sets of balls to provide lubrication to the balls. In this way, the linear guideway conceals two lubricating plates in the sliding block, which can maintain the length of the sliding block without affecting the stroke, and ensure that the running path does not produce a step difference, so that the smooth running of the ball can be kept consistent.