To increase flexibility and to improve a gripping property by forming dents in the bottoms of the positions proximate to the toe parts of shoe soles, thereby forming the bottoms thin.

The dent 2 of the shoe sole 1 exists in the bottom 4 where the body weights usually acts most exclusive of a heel part 3 and particularly in the central area of the bottom 4. The dent 2 preferably exists only at the bottom 4 and may also exist near to the heel part 3. The depth of the dent is so determined as to increase gradually from the boundary between the edges 5, 6 toward the center. The dent 2 is so formed as to have the depth gradually increased toward the center in a vertical direction (longitudinal direction) as well. Then, the shape of the dent 2 is domes as a whole. The maximum depth (b) of the dent 2 is confined within a range of 20 to 50% of the thickness (c) of the sole of the part. The width (v) of the dent 2 is confined within a range of 25 to 50% of the width (w) over the entire part of the shoe sole 1. The position thereof is so determined as to substantially exist at the center from the bottom 4.