An underarm float for infants, comprising a main body, the main body is composed of a front part and rear parts, which are connected to each other, wherein rear parts are connected to both ends of the front part, and rear parts at the two ends of front part are oppositely arranged; a first arc groove and second arc grooves are formed at the joint between front part and a rear part, first arc groove is downwards recessed along the upper surface of the front part and the rear part, and the second arc grooves are inwards recessed along the side surface of the front part and the rear part; a shoulder strap is arranged at the joint between the front part and the rear part, and the shoulder strap is located above the first arc groove; and the oppositely arranged rear parts are provided with an elastic cord.