Trust is one of the key factors that emerged as a significant concept in virtual communities. Trust is so complicated that it is hard to define in one standardized way. Trust issues have evolved into two major ways in the fields of virtual community and security. Among a huge literature concerning trust in virtual communities, a majority of literature addresses technical solutions on trust-building by providing new Web-based applications. They range from human users authorization, semantic Web, agent technologies and access control of network to W3C standardization for content trust and security. Some examples include AT&T’s Policymaker or IBM’s Trust Establishment Module (Blaze, Feigenbaum, & Lacy, 1996; Herzberg, 2000). Only a minority deals with understanding the concept of trust and sources of trust-building from social and cultural aspects. It appears to miss the essence of trust in virtual communities, although an integrated approach is needed for building trust in communication and the use of virtual communities. This article aims to present the definition of trust and relevant concepts for recognizing sources of trust-building in virtual communities. This article also presents future research implications for further development on trust and trust-building in virtual communities.