In the recent years, the microhardness techniques have found employed widespread applications in polymer research especially in the establishing structure-properties correlations. The technique has been increasingly used in the characterization of homopolymers, copolymers, polymer blends, and polymer composites. In this work, the materials investigated were microphase separated styrene-butadiene block copolymer systems and their blends with the corresponding block copolymer and homopolymer with the aid of the Leitz Microhardness Tester equipped with a square based pyramidal Vickers indenter. The morphology of the samples was studied by means of transmission electron microscopy (TEM). This book will be useful for the researchers working in the fields of block copolymers and nanomaterials with particular interest on the area of microindentation techniques and structures-properties correlations of nanostructured polymeric materials.