This study developed Japanese version of Effortful Control (EC) scale for adults, and examined its reliability and validity. In Study 1, a questionnaire survey of 209 college and vocational school students showed sufficient internal consistency and test-retest reliability for the scale. Its correlational validity was also shown in terms of the relationships with novelty seeking, harm avoidance, Five-Factor personality dimensions, depressive mood, and state anxiety. Study 2 was conducted to show that the EC scale measured not only self-concept but also actual executive attention function. Forty-seven undergraduates who participated in Study 1 performed a Stroop task, and the relation between magnitude of interference effect and EC scale score was examined. The EC scale as well as its two subscales was negatively correlated with the magnitude, indicating criterion-related validity of the scale.