One castellated and seven composite castellated beams are modeled using the software package SAP2000. The composite beams are modeled using link elements as shear connectors with stiffness of 100 kN/mm. For the composite models, one beam with 52 links, four beams with 26 link and two beams with 15 links are adopted with different positioning: above the openings, above the web-posts and uniformly along the beam. It was determent that the increase of shear connectors leads to increase of normal stresses in the corners of the first opening, where in comparison with castellated beam there is 30 % and 15 % rise for 52 links and 15 links above openings correspondingly for uniform load of 39 kN/m’. There is also a difference of 5 % between the stresses for links above openings and above web-posts, where the favorable position is that across the openings. According to the previous, the most commending beam will be with fewer shear connectors positioned above the openings. Therefor it can be assumed that it is best to design the castellated composite beam with partial shear connection, otherwise it would have to ensure full web near supports or increase the stiffness of the bottom part of the beam – concluding an optimized asymmetric section.