Abstract: In many critical application areas, such as military, legal and literature fields, methods of protecting copyright for text data could not cause any distortion in textual content. In this study, we evaluate a novel reversible (lossless) data hiding scheme for MS office 2007 document. The proposed scheme modifies the unnoticeable content and the synonyms of a document to hide information. While in extraction processing, the original content can be recovered without any distortion from the marked textual. Our scheme is achieved by using two common text information hiding methods simultaneously. The secret information is embedded into the cover document by synonym substitution. Original synonyms in the document are mapped into a compressed Synonym Index Table (SIT) and concealed into the MS office 2007 document. Experiments results demonstrated that proposed scheme can not only successfully embed and extract the secret information but also keep the original textual content undistorted.