A pneumatic tire having a specified rotational direction comprising, a tread portion provided with: a pair of circumferentially extending crown main grooves disposed on both sides of the tire equator; a plurality of inclined lateral grooves each extending axially outside of the tire from each crown main groove to each tread edge (Te) toward the anti-rotational direction to separate a plurality of shoulder blocks between crown main grooves and tread edges (Te); and a sipe (s), said inclined lateral grooves having inclination angles (θ1) of from 45 to 85 degrees with respect to the circumferential direction of the tire, said each shoulder block having a heel-side edge and a toe-side edge which comes into contact with a road later than the heel-side edge in the specified rotational direction, in a planer view, said heel-side edge smoothly extending in a curved manner from a first end intersecting a groove wall of said crown main groove to a second end intersecting said tread edge (Te) through a middle point which is a center between the first end and the second end in the axial direction of the tire, and all sipes provided on shoulder blocks terminating without connecting to heel-side edges, characterized in that said heel-side edge has a radius of curvature (Ra) of from 150 to 250 mm which is measured as a radius of curvature (Ra) of an arc (Ku) passing through the first end, the second end and the middle point, and by a crown land portion provided with crown lateral grooves, with the crown lateral grooves comprising first crown lateral grooves which are inclined at one side with respect to the circumferential direction of the tire, and second crown lateral grooves which are inclined at the other side with respect to the circumferential direction of the tire, and wherein the first and second crown lateral grooves (13a, 13b) are alternately arranged in the circumferential direction of the tire to separate a plurality of triangle shaped blocks in the crown land portion. a pair of circumferentially extending crown main grooves disposed on both sides of the tire equator; a plurality of inclined lateral grooves each extending axially outside of the tire from each crown main groove to each tread edge (Te) toward the anti-rotational direction to separate a plurality of shoulder blocks between crown main grooves and tread edges (Te); and a sipe (s), said inclined lateral grooves having inclination angles (θ1) of from 45 to 85 degrees with respect to the circumferential direction of the tire, said each shoulder block having a heel-side edge and a toe-side edge which comes into contact with a road later than the heel-side edge in the specified rotational direction, in a planer view, said heel-side edge smoothly extending in a curved manner from a first end intersecting a groove wall of said crown main groove to a second end intersecting said tread edge (Te) through a middle point which is a center between the first end and the second end in the axial direction of the tire, and all sipes provided on shoulder blocks terminating without connecting to heel-side edges, characterized in that said heel-side edge has a radius of curvature (Ra) of from 150 to 250 mm which is measured as a radius of curvature (Ra) of an arc (Ku) passing through the first end, the second end and the middle point, and by a crown land portion provided with crown lateral grooves, with the crown lateral grooves comprising first crown lateral grooves which are inclined at one side with respect to the circumferential direction of the tire, and second crown lateral grooves which are inclined at the other side with respect to the circumferential direction of the tire, and wherein the first and second crown lateral grooves (13a, 13b) are alternately arranged in the circumferential direction of the tire to separate a plurality of triangle shaped blocks in the crown land portion.