This literature review sets out to revisit the studies exploring impact of rater characteristics on language oral assessments. Three categories of raters' backgrounds: occupation, accent familiarity, and native language are identified and will be addressed respectively in the following sections. The results showed that no consensus regarding raters' occupational background, linguistic background and native-speaker status on examiners' rating has been found so far. However, this review will highlight the current testing situations, bring up limitations from previous studies, provide implications for both teachers and raters, and hopefully shed light on future research. / text