Membrane fusion between the viral envelope and host cell membrane is a key step for an enveloped virus entering into the host cell. The process involves intricate interactions between and conformational changes of viral envelope glycoproteins and corresponding cellular receptors. Herpesvirus contains many glycoproteins and different types of cellular receptors, the transformable receptor-glycoprotein complex constitutes a multipartite entry-fusion system. The molecular mechanisms of membrane fusion are generally regarded as the one of the most challenging issues in the study of enveloped virus. Much progress has been made recently in achieving a substantially improved knowledge base of this subject. A comprehensive review was presented on the structures and functions of important viral glycoproteins and receptors, formation of a receptor-glycoprotein complex during herpesvirus entry, and associated pathways. Detailed models of viral membrane fusion are also given. In addition, the prospect of future research is addressed.