The purpose of this study was to develop Japanese version of General Procrastination Scale (J-GPS) and to examine its reliability and validity. In Study 1, data obtained from 174 undergraduates were analyzed. Results showed sufficient internal consistency, factorial and concurrent validity with another procrastination scale. In Study 2, further data were obtained from 77 undergraduates. These data were analyzed to examine concurrent validity in terms of clinical and behavioral scales. Results indicated that J-GPS had a positive correlation with depression, anxiety, and actual procrastinatory behavior. These findings provided sufficient support for reliability and validity of J-GPS.