Emerging concern over social implications of large-scale adoption is a motivation to require certification of the sustainable origins of biofuels. In terms of the feasibility of biofuel supply in Japan, this study examines the behavioral intentions of sustainable activities by using social criteria of international levels in the context of bioethanol feedstock production in Khon Kaen, Thailand. The models adapted from the theory of planned behavior were tested by using the structural equation model. The main results are as follows: (1) In terms of the perception of working rights and conditions, which was largely influenced by the “awareness: real conditions” and “awareness: real conditions for the participants’ personal lives”, “personal norm” indicated the highest score. (2) “Education” had the greatest impact on solutions for personal welfare and well-being with respect to sustainable activities. (3) The scores of the importance for social welfare and well-being included six categories: reasonable compensation, reasonable working hours, healthcare and safety, fair treatment of all workers, good communication, and education with the similar ranges of scores and regression weights. (4) The “attitude toward the behavior” was the most influential predictor of “behavioral intention”. Results of this investigation give an implication to design a social criteria framework in agriculture activities such as the ethanol feedstock production.