It is thought to be important for student to develop ambivalence of the attitudes toward science related problems as an element of value inquiry ability. In this study, biology instructional models for value inquiry were applied to the middle school 2nd year girl students and then the effect of each instructional model on student`s ambivalence of the attitudes toward bioethics was studied. In the result, it was found out that student`s ambivalence attitudes have improved. Specially, the students of group presentation according to the value analysis model, role playing and debate, and discussion through web forum made significant progress in their ambivalence attitudes. On the contrary, the students of inculcation, and bioethical value clarification decision-making model didn`t make progress. In conclusion, biology instructional models for value inquiry are effective to improve student`s ambivalence attitudes.