To prevent an assistant side member from deviating to the center part of a tire at fastening a fastening member by forming the assistant side member of a surface side member annularly arranged along the tire circumferential direction out of rigid material, and providing the latched position of the fastening member on the connectors of the rigid materials of the assistant side member.

When a tire chain 10 is provided on a tire 10, at first cross chains 60... are wound on the tire in the width direction, a back side wire is annularly arranged along the circumferential direction of the tire 10, and then the connectors on both ends are connected to each other. Next, a surface side member 30 is annularly arranged along the circumferential direction of the tire 10, and then the lock hook 34 of an assistant side member 32 constituted by fluctuatably connecting together a plurality of rigid bars 321 through connectors 33 is latched onto the end part of a basic side chain 31. Thereafter, an elastic rope 72 is pulled to pull a winding chain 71, and the lock tool 73 is latched onto the lock hole 341 of the lock hook 34.