An experiment was conducted in the context of negative word-of-mouth to examine differences among social networking site (Facebook), personal blog, micro-blog (Weibo), and discussion forum in consumers' perceived credibility, brand attitude and purchase intention. Each of the 190 respondents was randomly assigned to one of the four eWOM platforms. Results showed significant main effect of the treatment on all dependent variables. Another intriguing finding was that consumers' perceptions of site credibility and source credibility were combined as one factor confirmed by factor analysis. This new factor, named as perceived eWOM credibility, is significantly differed among the four sites, such that the credibility of the eWOM message posted on personal blog was rated highest and discussion forum lowest, with micro-blog and social networking site rated between these. Interestingly and explicably, although the overall levels of brand attitude and purchase intention were low after reading the negative review, respondents assigned in discussion forum group showed slightly better attitude toward the brand and greater purchase intention than those exposed to other three eWOM platforms. Implications for both research and practice were discussed.