In this study it is aimed to investigate surfacial deterioration of Neogene volcanoclastics in Eskisehir-Yazilikaya area where the historical Midas monument is located. Influences of freezing and thawing cycles on physical and mechanical parameters of these rocks have been investigated by performing freezing and thawing test on the samples which have not been affected from deteriotation also by taking into account the climatic characteristics of the laboratory environment. Physical and mechanical tests have performed on both the fresh samples and the samples subjected to various numbers of freeze-thaw cycles. As a result, when the climatic conditions of the study area and the physical properties of the rocks are taken into account, it is found that freezing and thawing is a process of physical deterioration. Thus,:the fragmentation and degradation, observed on the surfaces of the rocks in the field, are also observed after freeze-thaw tests.