Aiming at utilization in broadcast services, we have developed an automatic conversion systems from Japanese to Japanese Sign Language. This system displays the sign language that translated as consecutive motions of CG character unlike usual language translation systems. However, the motions that were generated by the linear interpolation of the joint angles seemed unnatural as a human motion. We proposed a control technique to make the motion of the arms of CG characters smoothly, and we produced a correction function based on the technique. As a result of the evaluation of the corrected motions, we confirmed the efficacy of the technique.