Magnetism in speleological sites in the Republic of Croatia is extremely poorly researched although it is well known that cave sediments are well preserved. Two important Croatian speleological sites were selected for the research area, the longest site the Pit system „Kita Gaćešina-Draženova puhaljka“ and the pit „Slovačka jama“, the second in depth after the Pit system „Lukina jama-Trojama“. Measurement of material magnetism, i.e. magnetic susceptibility was measured in speleological sites with the Kappameter KM-7 and in the laboratory at the Croatian Geological Survey using Bartington MS2B System. Only soft sediment was measured and sampled at all locations. Profile locations were selected solely according to the availability of sampling. In the laboratory of the Department of mineralogy, petrology and mineral resources a characteristic sample was analyzed from each profile by X-ray powder diffraction method and one of them is separated into magnetic fractions by Frantz's magnetic isodynamic separator after which it was analyzed by stereoscopic lens. Analyzing magnetic susceptibility determined its measurability in speleological sediments. Significant changes in the values of magnetic susceptibility were observed on several profiles and explained by the differences in the mineral composition. The correlation of higher values of magnetic susceptibility with higher amounts of minerals containing metals is noticed. It has also been established that the two devices used in this paper are not compatible, they don't registere on the same samples equal or comparable values. Given the precision of the Bartington MS2B, it is assumed that the KM-7 Kappameter is not used properly or is not adapted to low temperature and high humidity conditions.