In this article we will describe and analyze the Umberto Eco’s concept on the iconic sign. The new manner of approaching and interpreting the iconic sign articulates its specific concept. This study is proving to be complex, that’s why this thematic segment will be observed in the future in several articles about this author. In the present article the problem of iconic sign’s conventionality is approached. Desite the classical platonic tradition of interpreting the image through a natural relation of resemblance, Eco finds sufficient arguments that argues that even the conventionality participates in the formation of the iconic sign. By reffering to certain examples this position will be passed through a critical analyze.