Stance and mediation, concepts of subjective implications, seem to be contradictory to the general expectations that news should be impartial and news translation faithful. The thesis, underpinned by Critical Discourse Analysis (CDA), Systemic Functional Linguistics (SFL), and Narrative Theory, develops an integrated analytical framework for the discussion of stance mediation in news translation through the examination of translations by Reference News (hereafter RN), a Chinese official news agency, of sensitive news discourse on events that happened in China in the year 2008. Focusing on the core narrative elements of stories on Tibet-related news events, the study adopts a descriptive and interpretative approach to the three-procedure analysis of stance mediation by drawing on Fairclough's model as the macro framework and adapting variables from the graduation system of Appraisal Theory and relevant framing strategies in Baker's model for the micro text analysis. Evaluative deviations are first described at textual analysis, both with detailed analysis of six sample news items and with a corpus-based comparison of 54 Chinese translated reports by RN and their 129 English original reports. The institutional practice of RN has been surveyed to interpret the evidenced mediation in the process analysis, before the target language context is explored for possible explanation. The study indicates that stance mediation does exist in the Chinese news agency, though it claims that all its translations are "faithful" to their source texts. While the quantification of the identified deviations in the corpus reveals a tendency of "positive Self-presentation" and "negative Other-presentation" in the translations, the sample analysis discovers that the mediation of stance depends on the accumulative discursive effect of different types of deviations. The process analysis establishes that the collective nature of the procedure of producing translated news texts at RN does not constrain but facilitate mediation . Mediation is found to be a necessity to reframe the narratives for the domestic readers who are in a social reality distinct from the original one. Based on the findings, the theoretical, empirical, and practical implications are discussed and some suggestions for future research given after summing up the limitations of the present study.