A motor of a ceiling fan includes: a shaft having two shoulder surfaces facing in opposite axial directions of the shaft, with the shaft coupling with a stator; and a bearing sleeve receiving two bearings for supporting the shaft, with an annular flange formed at an end of the bearing sleeve. The annular flange and one of the shoulder surfaces of the shaft clamp and position one of the bearings. A rotor has a housing coupling with the bearing sleeve, with the housing having a connecting portion. The connecting portion and the other one of the shoulder surfaces of the shaft clamp and position the other one of the bearings.