Since 1964, a comprehensive investigation of the sediments of the Quaternary and the Upper Pliocene has been in progress in the Hungarian Basin. A number of drillings with full core profit were sunk, one of them being situated near the community of Jászladány. This drilling attained a depth of 950 m (Fig. 2). The drilled material was extremely rich in fossil relics and offered the opportunity to study the climatic history of the Quaternary in the Hungarian Basin. Since this basin is a steadily subsiding part of the crust filled with limnic, fluviatile and eohan formations in which the erosion either plays a very small part or none at all, the climatic history appears to be complete. The individual very characteristic cycles of sedimentation (Fig. 1) permit also a clarification of the different stages of subsidence. In the boring of Jászladány, the Pleistocene has a thickness of 424 m, the Holocene of 8 m, thus the Quaternary altogether 432 m. This series consists of 10 cycles of sedimentation representing a step-like subsidence (Fig. 3). The sedimentary material is loam, silt and fine sand; medium-gramed sands are encountered only in the deepest complexes and at the borders of the cycles. The mineralogical composition of the sands shows 11 essential alterations of the denudation area, they are in relation with the reciprocal tectonic movements of the marginal regions. By means of paleontological data it is possible to distinguish, during the Quatertnary, 20—30 greater or smaller climatic changes. First-class proof for this fact is provided by the pollen which are present, 111 a very great number, in the samples extracted from the Quarternary. The great number of climatic periods of the Pleistocene can be classified into three major groups (Fig. 8):The layers from 8—129 m depth represent a climate period with generally cold and dry climate with a few humid and temperate periods. The layers from 129—285 m depth were sedimented during a moderately warm and generally dry climatic period. During the formation of the layers from 285—432 m depth, the climate was warm, at the beginning and the end it was moist, and in the middle dry for most of the time. The paleontological tables and figures Nos. 4—7 may serve as proof. A computation according to present crustal movements allows an estimation of 1.3—1.4 million years for the period of sedimentation of Quaternary layers.