Copyright © 2018 by ISFA S-shaped test piece has been proposed by China as a method to evaluate the finishing accuracy of 5-axis machining center. In this test, machining accuracy of a 5-axis machining center is evaluated by measuring the shape error of a workpiece machined by 5-axis simultaneous control of an inclined S-shaped part with a flat end mill. In this report, among the series of draft standards proposed by China, the method given in September 2016 which is the newest executable one is examined using a medium-size vertical 5-axis machining center and checked its validity.