An ankle protecting device comprises: a wrapping sheath having a lower-leg sheath, a foot sheath and a loincloth that are integrated with thereof, the loincloth constricts the wrapping sheath on a sole, an ankle and a lower leg and is adjustable for tightness thereof an internal supporting plate and an outer supporting plate fastened on the left and right sides of the wrapping sheath respectively, the shapes of the internal supporting plate and the outer supporting plate are symmetrical to each other, the internal supporting plate and the outer supporting plate (50b) elongate to be over the ankle along the internal and outer sides of the lower leg and then to the two sides of the sole toward the top of the sole and a foot bottom supporting plate fastened on the bottom of the foot sheath.
