The psychophysical and cognitive research is applied to the study of cartographic symbols recently, which was root in Peirce's semeiotic, a field focusing on logic of science. Based on MacEachren's triadic model of map signs, this study emphasizes a view from sign-vehicle through interpretant to reference, and employed semantic differential test to assess subject's attitude to decide the strength of relationship between sign-vehicle and reference. The results of this study revealed a high degree of consistency between association and legibility. While the relationship between familiarity and association as well as familiarity and legibility were moderate only. In general, the more negative semantics the more strong relationship was linked. Also, experience and gender affect the response significantly.