To develop and provide a method of reinforcing leather covers of a sewn ball which improves the durability of the sewn ball by reinforcing the segments of the sewing threads of the sewn ball by simple means, thereby imparting the strength equivalent to that of the leather covers to these segments.

The sewn ball formed by swing together a plurality of leather cover pieces (1a and 1b) are superposed with two sheets of the leather cover pieces 1a and 1b, are respectively provided with tapes on both surfaces near the end faces Y of these superposed leather cover pieces 1a and 1b and are sewn on the portions near the superposed end faces by sewing threads 3 (3a), by which the sewn segment are reinforced.