An adjustable vertebral spacer includes a spacer body, a movable member coupled to the spacer body, an adjustment ring mounted on the spacer body and rotatable to move the movable member and to further adjust the combined height of the spacer body and the movable member, a lock ring mounted on the spacer body for locking the movable member to the adjustment ring, and a top endplate coupled to the movable member at the top and tiltable to fit the angle of the adjacent upper vertebral body during surgery operation.