The main purpose of the current research work is to achieve an economical cold formed steel castellated beam with diamond castellation with limited buckling. In this way, to study the behavior of cold formed steel castellated beam with diamond castellation by the provision of different methods of placing the stiffeners for the sections is an main scope of the work. It can be achieved through this paper, which gives an Numerical, Analytical Study and Experimental investigation on the performance of cold-formed steel Castellated beams with Diamond Castellation shape. Perforations in web has been carried out to know its structural behaviour as simply supported beam under pure bending. The castellated steel beams with perforated web epitomize a new inventive which has occurred in the past span for the short- and medium length of beams. The Cold-Formed Steel provides a substantial weight reduction of these beams with castellation, compared to the hot-rolled beams. The Castellated Beam has made with 2 mm thickness CFS Steel, used all over the Beam. In the study, the Castellated Beam has been performed with three types of Stiffener Designs at web of the Beam. Beam with intercept Stiffeners plates at web has used. Both stiffened and unstiffened Castellated beam (Beam with Parallel, Perpendicular and intercept Stiffeners) were tested for numerical and experimental Testings. Finally, numerical analysis using ABAQUS 6.11 results are evaluated and the experimental results were confirmed with the results obtained from the finite element analysis. Based up on the numerical analysis and experimental investigation the different failure and buckling modes of the proposed beams has been studied and the load carrying capacity of beams has been predicted.