Surface enhanced Raman scattering (SERS) has attracted much attention since its discovery over 30 years ago because of its wide applications,such as in materials characterization,analytical chemistry,life and medical science.Various pure metallic nanostructures were proposed to act as SERS substrates for improving the Raman signals by taking advantage of the high surface volume ratio in nanostructures and the local surface plasmon resonance (LSPR) effect in noble metal nanoparticles (NPs).In particular Ag and Au NPs were often used as the high efficient SERS substrates due to their LSPR frequencies in the visible or near infrared regions,which lie in the measurement range of Raman.Since it is found that a Raman enhancement can be realized on semiconducting TiO2 NPs[1],more and more semiconductor-noble metal nanocomposites have been produced,such as ZnO/Ag,TiO2/Au and so on [2,3],to be used as the SERs substrates by taking advantage of both the SPR effect from metal NPs and charge transportation from semiconductors.In this work,a technique with the combination of the nanosphere lithography (NSL) and solution processes was proposed to fabricate a novel nanostructure so called urchin-like Ag NP/ZnO HNS arrays (Fig.1) as a highly efficient SERS substrate.This low cost and wafer scale technology exhibits the advantages of producing nanostructures in array distribution with uniform size and separation due to the merit of NSL method,and the fancy morphologies with an effective large surface area based on the solution process.In this hybrid nanocomposite a significant Raman enhancement (Fig.2) is achieved and understandably attributed to the formation of "hot spots",which were further proved by the theoretical calculation where an enhanced local electromagnetic field near the Ag NPs and the metal/semiconductor interface was characterized.