This book was originally written in 1998 and it encircles results of geology and petroleum geochemistry data in south-western edge of the Pannonian Basin. Experimental part was conducted in geochemical laboratory of Croatian oil Company INA, ltd. Unfortunately in last fifteen years exploration activities continuously decrease. This book is contribution to knowledge fund in this area, and it is updated with new collected data. Hoping those exploration activities will continue and rise in the future due increasing demands for energy, this book will be interesting for planners and performers of explorations. Also it could be interested for students of geology, geochemistry and petroleum engineering. Application of scientific principles in practice described in this book can give ideas for geoscientists in implementation of results of their scientific research in economy which enable better evaluation of their work.