This paper reports improvement of pressure tightness and the number of contraction of Rubberless artificial muscle. To improve pressure tightness, polyester sheet was sewn to make it a cylindrical shape. In addition, wrinkles on the air bag sheet are reinforced by Kevlar strings. The net sleeve was replaced to Clean CutR sleeve to avoid plastic deformation and flaying. By doing these improvements, the lifetime of displacement achieved over 200,000 times.