The cytokine, is a primary activator of early chemotactic cytokines, as well as of expression of adhesion molecules that ,facilitate migration of leukocytes into tissues.IL-1 is also. one of the most, active stimulators ,of osteoclast cells ,and lead to bone resorption.The aim of this study was to determined.the prevalence of the IL1 ? (+3954) gene polymorphism in a sample of Iraqi patients with chronic periodontitis in Babylon .,Province and to evaluater they association of this polymorphism with the severity of disease.