To provide a wheel come-off preventive device applicable for a low-floor hub.

In the wheel come-off preventive device, an inner cylinder 3L engaged with the low-floor hub 2L is formed to make an outside diameter of a portion opposed to a tire wheel 17L larger than an inside diameter of the tire wheel 17L, and formed with a support hole in a position corresponding to a recess 5L of an outer circumferential face of the hub 2L at a circumferential face, a stopper block 6L engaged with the recess 5L is supported removably in the support hole, and the inner cylinder 3L is provided with a collar 53L of a large diameter adapted to a shape of the low-floor hub 2L and having a diameter sufficient for covering an inside diameter side end of the tire wheel 17L.