Synopsis This book has been designed to serve as a text book for post graduate-students and research workers in earth sciences who require a background of and a feel for statistics and the theory of regionalised variables. Although the word geostatistics is used throughout Europe signalling the theory of regionalised variables as propounded by geoscientists at the Centre de Geostatistique, France, still it was considered necessary to include in this book some important classical statistical methods which are essential for modelling the processes concerning earth resource systems for optimum appraisal. First four chapters deal with the classical statistical methods including a discussion on Box-Jenkins models of time series analysis and next four deal with a discussion on the theory of regionalised variables and restricted upto Kriging (stationary case). Last chapter deals exclusively with the software developed for some of the problems. Practical application of these methods in earth sciences is explained at every stage. In all, it is hoped that this book would serve as a practical guide to geostatistics. The units of measurement used in the examples cited in the text are the real ones.