A necessity that is plays an important role in today's turbulent environment is e-commerce. E-commerce, despite being young has tremendous progress and especially recently, there has been more tendency in Iran. But on the other hand, since e-commerce is not tangible as traditional trade, one important requirement in the buying in e-commerce area is the concept of trust. Hence, this paper tries to investigate the relationship between trust and e-commerce that sometimes considered as a missing link in the e-commerce issues. This paper first discusses the concept of e-commerce and with a glance, explains the beginning of this type of e-commerce in Iran and examines the types and dimensions of trust. Then, the strategy of building customer trust and the importance of confidence in e-commerce was discusses. Building business to business trust and business to customer in e-commerce, the relationship based on mutual trust can be established and facilitate and expedite the process of e-commerce and its growth.