Studless tire

A studless tire (1) which is provided in the tread portion (2) with one or more circumferential portions (3) provided with V-shaped sipes (7), the total width of the one or more circumferential portions is in a range of from 10 to 25 % of the tread width (WT), each v-shaped sipe is composed of two parts extending from its vertex located in a central region of the circumferential portion, and the v-shaped sipes in each circumferential portion are oriented towards the same direction and arranged at intervals in the tire circumferential direction.