In order that the required manufacturing processes can be carried out, fixtures are developed to locate and hold a workpiece firmly in the accurate position. However, source errors of fixtures can change the accurate position and in turn, cause the locating error. It follows that the evaluation of locating error is important to fixture design. Therefore, a general approach to the locating error analysis is formulated for the first time. Firstly, a kinematic model and its algorithm of the locating error are proposed to analyzing the linear dimension based on the velocity composition law of particle movement. In addition, according to the relationship between the linear velocity and angular velocity, another kinematic model and its algorithm of the locating error are also formulated to verifying the angular dimension.