Analysing possibilities of indicating threats of earthworms for protection demands, it was shown that at the current stage of faunistical work it is not possible to choose the most threatened species in the Polish fauna, which could qualify to one of the threat of the European categories. In the case of this group of animals it is not possible basing, on current knowledge, to determine the category of threat. Although, it is assumed that there are four endemic species (e.g. connected with Carpathian Mts) in this group. The criteria stated in the Polish Red Data Book do not apply to oligochaete. Nearly none of the species can be characterized with demanded precision for chosen criteria, because the lack of quantity and quality data. It is only possible to distinguish „groups of non-determined species”, which are treated as „rare species”, but the lack of enough data does not allow to determine to which group they really belong. The determining of factors affecting the habitation of particular species belongs to a group of the least known subjects. A group of factor affecting one particular earthworm species was not considered yet.