Most research has used religious affiliation or participation to measure individual`s religiosity. However, the religious affiliation does not reflect heterogeneity of religious orientation among members with the same religious affiliation and measures of participation in religious activities do not consider the religiosity of oriental religions with no regular religious services. We need an appropriate measure to capture a variety of religious orientations of various religions. This kind of measure is also necessary to enhance the explanatory power of religiosity variable for social phenomena. Then, this study examine a measure which was considered to be appropriate for this purpose. Following Allport and Ross, Gorsuch and McPherson developed three dimensional measures of intrinsic-extrinsic religiosity. To examine the validity of these measures, empirical data collected for 827 subjects of high school students and their mothers were analyzed. The findings showed that original version of dimensionalization by Allport and Ross was better than that by Gorsuch and McPherson. In Korean situation, dichotomous approach of Intrinsic-Extrinsic religiosity seems to be more appropriate. For the greater generalization of this measure, we need more comprehensive social prejudice measures to examine I/E scale`s validity in the future.