Determination of the three dimensional (3D) structure of a protein can provide important details about its biological functions and mechanism of action. However, despite their significance, the precise three dimensional structures of most of the proteins are not fully determined till date. The main focus of the current review article is to gain a better understanding of the structural features of the proteins using computational techniques, and their relationship with function. Protein modeling and design is the method aimed to fold a primary amino acids sequence into protein structure with the ultimate goal of designing novel function and behavior. Moreover, proteins can also be designed from scratch or by similarity with the known protein structure. In the current article we have tried to cover various computer aided protein modeling and designing via homology and ab initio modeling, folding study using Molecular Dynamics (MD) methods and in silico mutation analysis.