Among representatives of the subfamily Microtinae (=Arvicolinae) -Myodes glareolus, Myodes rutilus and Craseomys rufocanus -an interspecies comparison was performed on haematological parameters characterising respiratory capacity of the blood, components of (non)specific immune defence and components of cellular haemostasis. C. rufocanus differs most strongly from the other two species by demonstrating higher counts of neutrophils, lymphocytes and platelets in peripheral blood and an increased number of "smaller" erythrocytes with high density of haemoglobin within the cell. The results are discussed in conjunction with the information available in the literature on basal metabolic rate of the species, their sociability and eurybionism, features of thermoregulation and phylogenetic relationships. The authors come to the conclusion that correct interspecific comparisons are possible only within the same reproductive-age groups (either immature under-yearlings or breeding voles that overwintered).