The invention provides a rain coat. The skirt of the rain coat is provided with a circle of inflatable air bags having inflation holes with sealing covers, and lacings are arranged at the connection positions of the inflatable air bags arranged on the skirt of the rain coat. When the rain coat is used, the lacings at the connection positions are fastened and air can be blown into the air bags to allow the air bags to bulge in all directions before the lacings at the connection positions are fastened together, so rain water on the coat can flow down along the skirt expanded in all directions and fall onto the ground to avoid wetting trouser legs during walking. Thus, the rain coat has an excellent rainproof effect.