Volume I/22A is the first of two volumes dedicated to nuclear binding energies and atomic masses of all nuclei. Related properties like the separation energies of single nucleons, or groups of nucleons, Q-values of alpha and beta nuclear reactions, and parameters of the residual interaction between nucleons, are considered as well. Also the experimental values are compared to the results of various model calculations. This comparison of experimental and theoretical results may help in the further development of nuclear theory. The data presented will also be of great significance for astrophysics and the understanding of the production of elements in the early universe. The present compilation was prepared by two eminent experts in the field. One of the characteristics of Landolt-Börnstein is that data are evaluated before they are accepted for compilation. The idea is to present ‘best values’ which can be used with confidence by non-experts. Volume I/22A contains the data for 1111 nuclei with Z ranging from 1 to 54. In view of the large amount of data available some of the information is given online only at www.springerlink.com (DOI: 10.1007/978-3-540-69945-3). Parameters for nuclear levels of many nuclei were previously published by Landolt-Börnstein in Volumes I/16, I/18, and I/19.