An exploration of context updating mechanisms from a cross linguistic perspective Presupposition is what people make use of on a daily basis. It is therefore crucial to comprehend how a presupposition gets projected in a sentence. This thesis focuses on three major presupposition projection mechanisms namely left right asymmetric symmetric and hierarchical approaches. For the reason that the majority of previous research is undertaken on the basis of English data this thesis evaluates these mechanisms employing Japanese and Chinese empirical evidence. The analyses and experimental data in this thesis confirm that firstly the left right asymmetric account which is substantiated by English empirical evidence is not tenable in Japanese and Chinese. Secondly the symmetric approach appears to be promising in both English and Japanese though it has not been sufficiently investigated. Thirdly the hierarchical framework can account for English Japanese and Chinese empirical evidence preliminarily. Much more attention should be paid to the hierarchical approach to presupposition projection in further studies. Further investigation into this topic can deepen the comprehension of human language and language processing.