This study was designed to confirm the validity of the Japanese version of the Identity Style Inventory. The three Identity Style scores (informational, normative, and diffuse/avoidant) were compared among the four groups of Identity Status (Identity Achiever, Moratorium, Foreclosure, and Identity Diffuse) based on the college students' data. Results revealed that the Identity Achiever and the Moratorium groups showed higher informational style score than the other two groups, and that the Identity Diffuse group showed the highest diffuse/avoidant style score of four groups. These results suggested that the Japanese version of the Identity Style Inventory was valid.