Abstract: Evidentiality is the linguistic representation encoding the source of the said proposition and indicating its credibility, and broadly defined, it also embodies the author’s assessment of information sources and involvement in the said proposition. This paper intends to explore how the author constructs text credibility by interpreting author’s pragmatic strategies in using lexical and sentential evidentials in specific texts according to the baseline of information reliability. The finding shows that the subjectivity of the source of information serve the author’s construction of the whole text, and therefore text credibility holds an unstable position in the territory moving according to the game between author’s pragmatic manipulation of text evidentiality and reader’s cognitive interpretation, and the rationality and appropriateness of author’s pragmatic adjustment of evidentials within the range of information reliability is weighted in determining text credibility. As linguistic markers of evidentiality in texts, the frequency of evidentials used in texts changes according to different styles’ need for credibility.