Based on the test of steel-concrete composite frame, the refined 3-D finite element (FE) modeling of steel-concrete composite frame was proposed by using Msc.Marc to gain a better understanding of the structural behavior of the composite frames. A number of material nonlinearities and contact nonlinearities, as well as geometry nonlinearities, were taken into account. Strain-based fracture criterion was adopted in the FE model to simulate the fracture of beam flange. The global and local behavior of the FE analysis models agreed well with those of the test specimens. Parametric studies were conducted on the basis of the refined FE model. The analyzed parameters included slab width, shear connection degree, axial force ratio, etc. The influences of these parameters on the behavior of the composite frame in terms of stiffness, strength and ductility were studied. It was suggested that the concrete slab width should be taken at least as a quarter of the beam span in the 3D FE model or in the test specimen to accurately evaluate the impact of the slab action. The axial force ratio had a great impact on the ductility of composite frame, while the thickness of the slab and shear connection degree had little effect on the seismic behavior of the composite frame. And some ideas for the corresponding design provisions were proposed.