To integrally form a swimming aid to be attached around the ankle with a web.

This swimming aid is composed of a cylindrical fastener part 20 for the ankle, a fan-shaped web 30 extended from the lower end of the fastener part 20 being opened downward and a plurality of ribs 40 radially provided at almost equal intervals on the outside surface of the fan-shaped web 30 so that a top end 42 can be protruded a little from an opening end 31 of the web while fixing a base end 41 on the lower part of the outer periphery of the fastener part 20 and the fastener part 20, the web 30 and a plurality of ribs 40 are integrally formed of rubber, synthetic rubber or plastic materials.