The lectures transcribed in Nobel Laureate Pierre-Gilles de Gennes's lecture note volume， Superconductivicy of Metals and Alloys， contain an unusually lucid，physical and original extension of the microscopic theory of Bardeen， Cooper，and Schrieffer (BCS theory) to take into account the role played by inhomo-geneity. As a result， they represent a lasting contriloution to our understanding of superconductivity， as generation after generation of graduate students and expe-rienced researchers in the field will attest. With the advent of heavy electron and organic superconductors， and especially with the ongoing extraordinarily high level of activity in the field of high temperature superconductivity， it is clear that research on superconductivity will continue to represent a significant portion of research in condensed matter physics for many years to come， and that researchers will continue to turn to de Gennes for enlightenment of the behav-ior of superconductors in a variety of interesting， real-world situations. I am accordingly very pleased that the publication of Superconductivity of Metals and Alloys as part of the Advanced Book Classics series will make it readily available to present and future generations of interested readers.