To fit in a curved spline shaft and be slidable freely.

A curve movement rolling guide unit comprises a spline shaft 2 extending in a state to be curved with a fixed curvature in a longitudinal direction; and a slider 1 fixed in the spline shaft 2 and effecting curve movement. The slider 1 comprises a casing 3; end caps 4 attached to the two end faces of the casing 3; and an end seal 5 attached to each of the end faces of the cap 4. The casing 3 has a track groove 7 and a return passage in the inner peripheral surface on which rolling bodies 6 are rolled. The casing 3 is divided into two sections along a longitudinal direction and comprises a pair of casing members 13 and 14 the division surfaces 16 of which are brought into contact with each other for securing.