This paper presents an automatic techruque of suitable reference potential selection for quantitative EEG interpretation. The 16-channels EEG recording under mono-polar derivation is analyzed. There are two prejudgments defined for checking the amplitude distribution and ear lobe activation. After prejudgments, the EEG is classified into several cases in cluding diffused case, non-diffused case, and artifact contami nation case. Due to the cases, an automatic reference selection method is applied in order to find out suitable reference potential. Finally, the referential derivation constructed according to the obtained reference potential, is evaluated for further EEG rhythm analysis. The presented technique can high light the EEG rhythm of interest,which is useful for quantitative EEG interpretation by both visual inspection and automatic evaluation.