The Electronic Properties Information Center has developed the Data Table as a precis of the most reliable information available for the physical, crystallographic, mechanical, thermal, electronic, magnetic and optical properties of a given material. Data Tables serve as an introduction to the graphic data compilations on the material published by the Electronic Properties Information Center, EPIC, as Data Sheets. Although the Data Sheets are principally concerned, according to the scope of the Center, with electronic and optical data, it is believed that data covering the complete property spectrum is of the first importance to every scientist and engineer, whatever his information requirements. The enthusiastic reception of these Data Tables has confirmed this opinion and increasing requests for this highly selective type of information has resulted in these III·-V Semiconductor Compounds Data Tables. The major problem in this type of selective data compilation on a semiconducting material, lies in the material purity. Properties may vary so widely with doping, crystallinity, defects, geometric forms and the other parameters of preparation, that any attempts at comparison normally fail. On this basis, we have consis­ tently attempted to give values derived from experiments on the highest purity single crystals or epitaxial films. At the very least, these data should be reproducible and this gives the data their principal validity. If such values however, are not available, then the next best data are reported, together with material speci­ fications. These latter include the carrier concentration and the dopant.