Although steel-concrete interface has significant influence on bonding strength and shear strength, the composite structure with the consideration of the interface fracture has been rarely conducted. In this study, sensitivity analyses are performed to find out steel-concrete interface characteristics by using interface finite elements, defined as elastic-plastic behavior. In order to verify computational accuracy, the analyzed interface properties are compared with experimental results. Generally, interface in steel-concrete composite structure plays a critical role of controlling bonding strength as well as transferring loads between steel and concrete. The composite interface should be avoided to reach to an interface fracture condition; otherwise composite structure may deviate from intended behavior even under low stress state. It is then led to catastrophic fracture or collapse of the structure. This study shows that interface properties of steel-concrete can be analyzed by using the interface element, and the results provide more reliable prediction for the steel-concrete composite behavior.