To obtain uniform pants for baseball capable of eliminating discomfort due to stuffiness without impairing durability and wearing feeling of cloth material and free from penetration of sand from between cloth material or free from breakage of cloth material.

The uniform pants 1 for baseball are obtained by providing an openable belt 4 having many openings in the inside part of a thigh and the openable belt 4 occupies parts of lateral two triangles 41 and 42 obtained by binding cross point 51 of the thigh inside which is an intersection between the thigh side line 5 and crotch line 6, a point 52 of 5-10 cm on crotch line from the cross point 51 of the thigh inside and points 53 and 54 near right and left knees on the tight inside.