As a source of information and an indicator of authors’ attitude, evidentials indicate the authors concern for the credibility of information. Evidentials can be regarded as persuasive resources of building ethos. Drawing on the distribution of evidentials in different moves of English research articles, this study analyzes the way that evidentials build ethos in different moves of English research articles. This study finds that authors select different evidentials to build their ethos in different moves of English research articles so that readers trust in their wisdom, virtue and goodwill, aiming to enhance their academic credibility and the persuasive effect of discourse.