Some years after the publication of Vol. III/11 and itssupplement III/18 dealing with elastic, piezoelectric,pyroelectric and optical properties of crystals, a completerecompilation of the data of these volumes and of new datawas performed. Because of the growth of this subject matterit was found convenient to divide the material into fourvolumes, III/29a and b forthe low frequency properties andIII/30a and b for high frequency propertiesof dielectriccrystals. The first subvolume III/29a, already published in1992, contains exclusively second and higher order elasticconstants including temperature and pressure coefficients.The present second subvolume III/29b essentially containsrelative dielectric constants and piezoelectric constantsand their temperature coefficients, as well aselectrostrictive and pyroelectric coefficients andelectromechanical coupling factors of dielectric crystals.The data are given in numerous tables and figures, thelatter mostly showing temperature and compositionaldependences. An alphabetical index for all substances ofboth subvolumes listed according to their element systemsand furthermore an index of chemical, mineralogical, andtechnical names help the reader to find data.