A circulation module of a linear guideway for being installed on a sliding block, comprises two circulation tubes each having a fill-in opening, two rolling units respectively arranged into the circulation tubes via the fill-in openings, and two separating sheets respectively installed on the circulation tubes to shield the fill-in openings. When the circulation tubes coupling through the sliding block, the fill-in openings respectively expose from two opposite ends of the sliding block, and part of each rolling unit arrange out of the corresponding circulation tube is disposed on the sliding block. Thus, the instant disclosure provides the circulation module for receiving the rolling units quickly and simplifying the construction of an end cap module mating thereto. Moreover, the instant disclosure also provides a linear guideway.