A studless tire which is provided in the tread portion with one or more circumferential portions provided with V-shaped sipes, the total width of the one or more circumferential portions is in a range of from 10 to 25% of the tread width, 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.