PURPOSE: To improve ice and snow performance without inviting biased abrasion by extending a large number of sipes cut into respective blocks in a longitudinal block group in zigzag like along peripheral edges of a tread, while making at least respective one-side ends thereof open to lateral grooves.

CONSTITUTION: A central peripheral groove 1, a pair of peripheral grooves 1a for holding the above between them, and numerous lateral grooves 2a-2c for connecting these respective peripheral grooves 1, 1a and tread ends to each other are respectively arranged on a tread T, therewith the tread T is divided in a longitudinal block group B consisting of numerous blocks 3a-3c. A large number of sipes 5a, 5b cut in from respective lateral grooves 2a-2c are arranged in respective blocks 3a-3c. In this case, respective sipes 5a, 5b are made to extend along the peripheral edges of the tread T in zigzag like, while the sipes are made to open at least respective one-side ends of respective ones to respective lateral grooves 2a-2c. Thereby, traction performance and turning performance on snow and ice are improved without inviting biased abrasion of a tire.