We present our efforts on the interrogation and understanding of surface plasmon polaritons (SPPs) and their applications to light harvesting in two classes of nanostructures.Firstly we will discuss SPP propagation properties in heterostructures composed of metal and ZnO as well as their derivatives sandwiched with metallodielectrics.Various mechanisms responsible for the enhanced photoluminescence are explored.A strong surface plasmon mediated light emission from metal/ZnO heterostructures with good ohmic contact is accomplished.