To provide a portable rain cover for a bag that can be used in two ways as a portable protective rain cover carried for protecting a bag in the rainy weather, and as a shopping bag carried in the bag in the normal time when it is not used as a waterproof cover, solving the problem that so far a portable protective rain cover for a bag is folded and carried in the bag for the rainy weather, and is only used as a waterproof cover for covering the bag in the rainy weather, thereby becoming too much to carry when it is not used as a waterproof cover in the rainy weather since it has to be folded and carried.

In a portable rain cover for a bag, a body is composed of a boxy body cover of a vinyl or polyester waterproof material, and the bottom of the cover is an opening/closing part, to which an opening/closing fastener, a lid to cover the opening/closing part, and some pieces of stoppers for closing the lid are provided. The top face of the bag body is provided with a grip and a button hole. A button for fixing the grip is provided inside the top face of the bag body.