A simulator for training manual arc welding operation by means of mixed reality technique was proposed and discussed in the previous paper. According to the experimental training results with the simulator in it, most trainees could not gain the skill of electrode tip positioning so well, though they could gain the skill of moving speed and angle control of the electrode. In this research, the authors investigate the reason for the less effectiveness and the solutions. As the results, it is found that in the conventional system, the trainees have difficulty in perception of electrode tip position, because of its inaccurate drawing in the real environmental image and two dimensional visual displaying. To improve the drawing accuracy, the camera for video-see-through HMD is replaced with high resolution ones and the multimarker position detection system is adopted. In addition, a stereo vision HMD with an easy vergence angle adjustment function is adopted to give the trainees three dimensional image. The experiments with the improved simulator show apparent reduction of the position-perception error of electrode tip and effective training.