The chain lock of the present invention includes a lock body and a linkage chain. The lock body has a combination lock core and a socket, wherein the combination lock core has a plurality of discs. The linkage chain is formed via linking a plurality of link plates and has a first end portion and a second end portion, wherein the first end portion is joined with the lock body. The second end portion can be inserted into and secured to the socket. The combination lock core locks the second end portion when the second end portion has been inserted into the socket The linkage chain can be wound around the lock body when the second end portion is unlocked.