In 1979, a conference on x-ray microscopy was organized by the New York Academy of Sciences, and in 1983, the Second Interna tional Symposium on X-ray Imaging was organized by the Akademie der Wissenschaften in Gottingen, Federal Republic of Germany. This volume contains the contributions to the symposium "X-ray Microscopy '86," held in Taipei, Taiwan, the Republic of China in August 1986. This is the first volume which intends to provide up-to date information on x-ray imaging to biologists, therefore, emphasis was given to specimen preparation techniques and image interpreta tion. Specimen preparation represents a major part of every microscopy work, therefore, it should be strongly emphasized in this emerging field of x-ray microscopy. Theoretically, x-ray microscopy offers the potential for the study of unfixed, hydrated biological ma terials. Since very few biological system can be directly observed without specimen preparation, we would like to emphasize that new information on biological specimens can only be obtained if the speci men is properly prepared. In the past decade, many of the published x-ray images were obtained from poorly prepared biological speci mens, mainly air-dried materials. Therefore, one of the goals of this conference is to bring the importance of specimen preparation to the attention of x-ray microscopy community. X-ray microscopy can be subdivided into several major areas. They are the classic x-ray projection microscope, x-ray contact imag ing (microradiography) and the more recent x-ray scanning micro scope, x-ray photoelectron microscope and x-ray imaging microscope."