To improve a pattern noise by reducing an impact sound and an air-column resonance sound while suppressing a pumping sound.

A block 6 formed by circumferential grooves and transverse grooves includes: acute-angled crossing portions 7a in each of which the transverse groove and the circumferential groove make an acute angled crossing by the transverse groove inclined by an angle θ of 5-40° with respect to the tire axial-direction; and obtuse-angled crossing portions 7b in each of which the above two grooves make an obtuse angle. A block wall surface facing the transverse groove is provided with at least two slits 9 having a width of 0.3-2.0 mm. An acute-angle-side distance P2 measured along a block edge 6e from the acute-angled crossing portion 7a to the width center of a slit 9a on the acute angle side nearest to the acute-angled crossing portion 7a is made larger than an obtuse-angle-side distance P1 measured along the block edge 6e from the obtuse-angled crossing portion 7b to the width center of a slit 9b on the obtuse angle side nearest to the obtuse-angled crossing portion 7b.