A method is introduced for calibrating the kinematic parameters of articulated arm coordinate measurement machines (AACMM) to improve its accuracy. The kinematic model of AACMM is firstly built according to Denavit-Hartenberg method. Then specific kinematic parameters and the errors of which are analyzed. A nonlinear programming genetic algorithm is adopted to seek the global optimal solution of the kinematic parameters. Computation result indicates that the method can be used to implement the calibration precisely and quickly.