With the development of the electronic commerce, the electronic word-of-mouth (eWOM) has become important reference information of the consumer shopping. EWOM has attracted considerable interest from researchers in the past decade. There are plenty of academics who looked into what factors play the important roles in effect of eWOM. In this paper, a research review is conducted and an integrated framework is proposed on effects of eWOM. The effects of eWOM are influenced by the characteristics, communicators, and other factors. The characteristics of eWOM include the source, the volume and the valence. The communicators of eWOM refer to the sender, the receiver and the relationship between them. In addition, dispersion and consistency, persistence and observability, anonymity and deception, and community engagement are related factors for effect of eWOM.