Non-pneumatic tire

Disclosed herein is an airless tire which absorbs shock and holds pressure applied to the tire through an auxetic spoke buffer (30) without using air pressure. The airless tire includes a cylindrical tread (10) being in contact with the ground, an axle fixing section (20) having a smaller circumference than the tread and disposed inside the tread, and an auxetic spoke buffer connecting the tread and the axle fixing section and providing a buffering function. Accordingly, the airless tire is transformed only to an extent to properly function as a tire when the spoke buffer is transformed by pressure or impact and fully returns to an original shape when pressure or impact is removed.