A channel module of a linear guideway includes a slider, two circulators, and two wire holders. The slider has two opposite inner loading surfaces. The circulators are respectively installed on two opposite sides of the slider and respectively connected to the inner loading surfaces. Each circulator includes an outer loading surface and two corner portions respectively extended from two opposite ends of the outer loading surface to two opposite ends of the corresponding inner loading surface. Each corner portion has a corner surface and a connecting surface. In each corner portion, an altitude difference is formed between an end of the corner surface connected to the connecting surface and the adjacent inner loading surface. The connecting surface is connected to the corresponding inner loading surface seamlessly for eliminating the altitude difference. The wire holders are respectively arranged adjacent to the inner loading surfaces.