The Xˉ and R control charts have been used as an effective tool for carrying out process control from the standpoint of statistical quality control. However, the 3σ method is not so powerful in testing arousing a feeling of dissatisfaction particularly when controlling production processes. In other words; when process shift is not so great, the Xˉ ,and R control charts does not have a strong power of test and it is sensitive to dispersion, showing the possibility of carrying out wrong control. Hence,the purpose of this paper is to study the characteristics of process adjustment on the basis of the Xˉ and R control charts, and we have proposed the run method as a measure to remove these defects of the charts.