The excavation of Lepcis Magna and of Sabratha has yielded a number of inscriptions that document the supply and use of marble for architectural purposes under the Roman Empire. The texts of these inscriptions will appear shortly in the collection, ‘Inscriptions of Roman Tripolitania,’ which is now being prepared by Miss J. M. Reynolds and the writer for publication by the British School at Rome (referred to hereafter as IRT). Few of them have been previously published, and of none has the significance been discussed. They have, however, an important bearing both on the architectural and on the economic history of their times; and the pages that follow are an attempt to indicate something of their character and significance, and to suggest further useful lines of inquiry.