Based on the geological material obtained mostly from the central zone of Kyusyu with which the writer is relatively well acquainted, he has formulated and endeavoured to examine some hypothetical principles of geology., (1) The first principle is that of qualitative change of earth's crust., The area which has become central Kyusyu in Holocene, may have been a part of a major geosyncline in Palaeozoic era, and it became a part of the Oga tectonic zone in a certain age of the Mesozoic era., Then, during the period from the middle Cretaceous to the early Tertiary, it was a "labile Schelfe", and since the Neogene Tertiary, it has become the landmass which resembles a "stabile Schelfe" or a "Block"., (2) The second principle is that a major tectogenic unit may possibly differentiate, in the course of the geological evolution, into minor and new tectonic units., (3) Kind and forms of geological Phenomenon, as well as its three dimensional extent are changing from time to time., In some cases, a new geological event happens in a new area apparently (or essentially ?) independent of the old area where another event had occurred., (4) There can be no permanent concept of geotectonic division that can be applied to all the geological events which are related to a certain area under concideration., To search for the essence of geological phenomena, such method of geotectonic classification as that of looking at the combination of various rocks which are only the final remnant of products of geological evolution, a method which reflects a static standpoint of view, cannot be upheld., These hypothetical principles or ideas should be actually proved later on and need some revision in future.,