HEAVY DUTY PNEUMATIC TIRE

A heavy duty pneumatic tire including a tread portion provided with a plurality of circumferentially extending main grooves (4, 5, 7, 8) and a plurality of land portions separated by the main grooves (4, 5, 7, 8), the land portions include a shoulder land portion (13) formed into a circumferentially continuous rib and having a tread edge, a first middle land portion (21) adjacent to the shoulder land portion (13), and a second middle land portion (22) adjacent to the first middle land portion (21), the first and second middle land portions (21, 22) are formed into a row of first and second middle blocks (25, 27) separated by a plurality of first and second middle lateral grooves (24, 26), respectively, wherein each first middle block (25) has a circumferential length (L1) greater than that (L2) of each second middle block (27).