FOR A PLANAR THREE DEGREES OF FREEDOM REDUNDANT MANIPULATOR, AN OPTIMAL DESIGN FOR THE DETERMINATION OF MANIPULATOR PARAMETERS WAS CARRIED OUT WITH FOUR PERFORMANCE INDICES AS OBJECTIVE FUNCTIONS. HERE THE MANIPULATOR PARAMETERS REPRESENT NOT ONLY FOR LINK LENGTHS AND MASSES BUT ALSO JOINT MOTORS WHICH MUST BE TREATED AS DISCRETE VARIABLES. THE PERFORMANCE INDICES ARE AS FOLLOWS: MANIPULABILITY INDEX, CONDITION NUMBER OF JACOBIAN MATRIX, MOVING ACCELERATION RADIUS, AND ISOTROPY INDEX OF THE MOVING ACCELERATION POLYGON. AS OPTIMIZATION ALGORITHM CONTAINING CONTINUOUS AND/OR DISCRETE VARIABLES, THE ITERATIVE ORTHOGONAL ARRAY BASED OPTIMIZATION WHICH USES ADDITIVE MODEL OF TAGUCHI IS NEWLY PROPOSED. FROM THE OPTIMIZATION RESULTS, IT IS FOUND THAT THE SECOND AND THIRD LINKS ARE RECOMMENDED TO HAVE THE SMALLER LENGTHS FOR THE MORE VELOCITY CAPABILITY OF THE END EFFECTOR. AND FOR THE MORE ACC