We describe a schema matching algorithm EXSMAL that automates the semantic correspondence discovery between the EDI (Electronic Data Interchange) messages of various standards (EDIFACT, SWIFT…) by using XML Schema as the pivot format. This algorithm takes two schemata of EDI messages as the input, computes the basic similarity between each pair of elements by comparing their textual description and data type. Then, it computes the structural similarity value basing on the structural neighbors of each element (ancestor, sibling, immediate children and leaf elements) with an aggregation function. The basic similarity and structural similarity values are used in the pair wise element similarity computing which is the final similarity value between two elements.