There are provided a link mechanism analyzer for performing a performance confirmation or test on a simualation basis for link mechanism produced using a CAD system for a mechanism design, and a link mechanism joint data arithmetic apparatus for evaluating joint data describing a parameter representative of a couping relation between a link of the link mechanism and a joint, which parameter is referred to as, for example, a Deravit-Hartenberg's link parameter, and a parameter value of the paramerter. The evaluation of such a joint data will be needed when a performance confirmation or test on a simualation basis for the link mechanism is performed using the link mechanism analyzer.