The pneumatic tire of the present invention characterized by comprising: bead cores provided on a pair of right and left bead portions, respectively, a carcass ply extending from a crown portion to the both bead portions through both side wall portions and moored to the bead cores, an inner liner disposed at an inner side than the carcass ply in a direction of a tire diameter, and a tread disposed at an outer side than the carcass ply in a direction of a tire diameter and having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5% or less at elongation by an applied stress of 3.0 MPa and a glass transition temperature of -20°C or lower, and the crosslinked rubber composition of the present invention having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a glass transition temperature of -20°C or lower are excellent in abrasion resistance.