Abstract: : The use of composite structures is increasingly present in civil construction works. Steel-concrete compositebeams, particularly, are structures consisting of two materials, a steel section located mainly in the tension region and aconcrete section, located in the compression cross sectional area , both connected by metal devices known as shearconnectors. The main functions of these connectors are to allow for the joint behavior of the beam-slab, to restrictlongitudinal slipping and uplifting at the elements interface and to take shear forces. This paper presents 3D numericalmodels of steel-concrete composite beams to simulate their structural behavior, with emphasis on the beam-slab interface.Simulations were carried out using version 14.0 ANSYS code, based on the Finite Element Method. The results obtained werecompared with those provided either by Standards, experimental work or found in the literature, and such comparisondemonstrated that the numerical approach followed is a valid tool in analyzing steel concrete composite beams performance.Keywords – ANSYS.14, composite beams, shear connectors, numerical modeling, finite element