Historical geography of Persian Gulf has still unknown points despite of conducted researches. The texts of Sif can be offered the new information about cultural interaction history of this region. Term Sif has been utilized for description of northern coasts of Persian Gulf. In other words, this term has been mentioned as Arabic word in encyclopedia. The present study investigates not only the relationship between Sif term and the historical geography of northern coasts of Persian Gulf due to the necessity of the role of historical geography in researches related to the terms but also the examination of changes of Sif. The evidences based on linguistic, historical and geographical data reveal that term "sif" has origin in historical geogr...