Abstract: The conservation law of second-order nonholonomic system of non-Chetaev’s type was studied by means of the Jourdain’s principle. The invariant condition of Jourdain’s principle under infinitesimal transformation is given by introducing Jourdain’s generators. Then the conservation law of the system is obtained under certain conditions. Finally a calculating example is given.

Key words: Jourdain’s principle, nonholonomic system, conservation law