Abstract: In the present linear guide bearing, the center of curvature O′ of a ball reversing passage 27 is shifted to a return side ball passage 25 side by a given amount m when compared with the center of curvature O′ of a conventional guide bearing. Due to this, not only the radius of curvature of a concave-arc-shaped groove 29 formed in each end cap 9 is reduced by a given amount m but also the concave-arc-shaped groove 29 is shifted to the return side ball passage 25 side by a given amount m, when compared with the conventional guide bearing. Thus, an angle &agr; formed between a line connecting the leading end of a tongue portion 31 to the center of curvature O′ of a ball reversing passage 27 and the moving-direction end face of a bearing main body 7, can be reduced significantly when compared with the conventional bearing.