In online transaction, it is difficult for customers to have trust when dealing with a web vendor that they never interact with and is not known in a market. Without a specific knowledge about a web vendor, Word-of-Mouth (WoM) is one of the powerful sources of information which can be used to convince customers, via social actor and network, to trust the vendor. McKnight and colleagues who are among the first studying trust have based on Mayer’s trust definition and constructed trust by dividing it into two separate components (i.e. trusting beliefs and trusting intention). Their trust model had been included and extended with several essential trust antecedents, however, it can be further improved by adding other construct, that is, WoM. This paper is primarily aimed to formulate an extended McKnight’s trust model by adding the WoM in examining its effect on trusting beliefs and trusting intention. This study proposes that a positive WoM about a web vendor leads to a customer strongly perceives that the vendor will behave trustworthily and increases the customer’s inclination to rely on the vendor. The paper also proposes the methodology to validate this model. A conclusion with study’s contribution and limitation end this paper.