In general, a counterweight or a fluidic cylinder is employed for gravity compensation to resolve the poor positioning performance on a vertical motion stage in machining process. Therefore, a novel zerogravity vertical motion mechanism for precision machining was developed. The proposed mechanism was driven by the linear motor,the moving stage and the counterweight were supported by the magnet yoke and rolling guideway. Due to the inertia of moving parts was doubled for disturbance, the mechanism could minimize the influence of machining force effectively. The performance evaluation results show that, the mechanism provides superior driving characteristics to vertical motion stages.