聽障生的閱讀能力不如同年齡的聽人，在國內外是研究上肯定的現象。本研究假設以手語為母語的聽障生在閱讀聽人的書籍時，彷彿是EFL學生學習另一種語言，一方面必須重新學習，另一方面會受母語(手語)干擾。本研究將由閱讀歷程中的重要因素—句法（一般句法，手語句法，混淆句法），探討手語聽障學生閱讀書面語的現象。實驗一操弄手語的句法，探討手語與口語聽障生在表達符合文法手語的文章時，受到其母語的干擾程度；實驗二延續研究一，操弄文章的句法，並且提高文章難度，檢視手語聽障生閱讀文法手語的書面語時，其組間變項為文章的句法受到干擾的情形。研究結果顯示，實驗一的結果並未符合本研究的假設，也就是在一般句法上，手語組並未受到比口語組要多的干擾。然而在提升文章難度後，口語組和手語組在一般句法與手語句法的閱讀表現均有差異，且皆是手語組理解成績優於口語組，亦與本研究假設不合。但是，一般句法的干擾與兩組理解成績均有顯著負相關，顯示句法對理解的影響力。本研究假設書面語是手語組學生的外語，手語是口語組的外語，只有口語組的結果驗證假設。為何手語組學習書面語不符合假設，需要進一步探討。至於句法與閱讀理解的關係，由干擾數與閱讀理解成績的顯著負相關看來，本研究肯定句法與閱讀理解的關係。 The reading achievement of hearing-impaired is inferior to same aged listeners. It is a very positive phenomenon across literatures. Actually there are two groups of hearing-impaired students. One who signs at home, and sign language is one’s mother tongue. The other one who is taught to communicate by oral and signs less. The last group will be named oral group in this study. It is assumed when a hearing-impaired child grown up with sign language to read books is like an EFL student learn to read English texts（Wilcox, 1999）. Based on this hypothesis, this research will probe the role of syntax on hearing-impaired who reads written language, for syntax is the back bone of texts. Study 1 adopted the paradigm of interference by posing sign language grammar and written syntax to both sign and oral hearing-impaired students. Their job is to express correct grammar of articles with either sign grammar or written syntax. Study 2 is to follow study one, but to enhance the difficulty of grammar to further prove the role of syntax on reading. The findings showed that both study results did not match our assumption. This research assumes that written language is the foreign language for sign group students, and sign language is the foreign language for oral group students. It needs further research to clarify why. However, the interference of syntax and the reading comprehension scores of two groups both have a significantly negative correlation. That reveals the syntax influence on reading understanding. Application of the result for teaching and learning is detailed in the study.