Disclosed is a pneumatic tire enabling to even a weight balance thereof in a tire circumferential direction in realizing reduction of cavity resonance noise by using an annular object having cross-sectional areas which vary depending on locations in the tire circumferential direction. The pneumatic tire of the present invention is one in which an annular object having cross-sectional areas which vary depending on locations in the tire circumferential direction is mounted on an inner surface of a tread portion. In the pneumatic tire, the annular object is formed by partially applying compression forming to a porous material member having a density of 5 to 70 kg/m3 and having an uniform cross-sectional shape in the tire circumferential direction.