The aim of the research is to identify the patterns of chemical identity thinking and the significance of the difference in these patterns between the students of the research sample.The research sample consisted of (200) students from the fourth year of the University of Baghdad, College of Education for Pure Sciences / Ibn Al-Haythem/ Department of Chemistry in the morning and evening studies. That is, by (50%) of the research community, and the research tool was a test of chemical identity thinking patterns from (20) items with four patterns: (objectivization thinking pattern, principlsim thinking pattern, compositionism thinking pattern, interactionism thinking pattern).