Abstract: Use of castellated beam for various structures rapidly gaining appeal. This is due to increased depth of section without any additional weight, high strength to weight ratio, their lower maintenance and painting cost. The principle advantage of castellated beam is increase in vertical bending stiffness, ease of service provision and attractive appearance. However one consequence of presence of web opening is the development of various local effects. In this paper a steel section is selected, castellated beams are fabricated with increase in depth of web openings. Experimental testing is carried out on beam with two point load and simply supported condition. The deflection at centre of beam and various failure patterns are studied. The beams with increase in depth are then compared with each other and with parent section for various parameters and for serviceability criteria. The widespread use of castellated steel beam as a structural member has prompted several investigation in their structural behavior. Castellated beams have proved to be efficient for moderately loaded longer spans where the design is controlled by deflection.