Control charts are generally used for process control, but the role of traditional control charts have been limited in case of a contaminated process. Traditional $ar{x}$ control charts have not been activated well for such a problem because of trying to control processes as center line and control limits changed by the contaminated value. This paper is to propose robust $ar{x}$ control charts which is considering a location parameter in order to respond to contaminated process. In this paper, we consider $ar{x}_{alpha}$, that is trimmed rate; typically ten percent rate is used. By comparing with p, ARL value, the responding results are decided. The comparison resultant results of proposed two control charts are shown and are well contrasted.