The astronomical commentary of Stephanus of Alexandria is an important marker in the history and the transmission of Ptolemy's Handy Tables. Following the example of the Small Commentary of Theon of Alexandria, Stephanus however adjusts the tables and the astronomical data to the geographical coordinates of Byzantium. The treatise presents a problem of attribution because it's anonymous in most manuscripts. The text shows also small additions from the emperor Heraclius Ist. We are preparing a critical edition of the commentary. These (...) study presents several results of our work. (shrink)