The article discusses the peculiarities of the clinical-laboratory pattern and mechanisms of disfunction of phacytizing blood cells in children aging from 3 to 14 with pseudotuberculesis of medium severity with smooth and recurrent clinical course. It is shown that the clinical manifestations of children pseudotuberculesis, regardless of the age and clinical course, are characterized by syndromes of intoxication, exanthema, affection of the gastrointestinal tract, increased liver. The blood is characterized by the increased ESR, increased numbers of neutrophils, monocytes, eosinophils, indices of liver affection. The disturbance of the functional activity of blood phagocytes is caused by the increased absorbing capacity of monocytes and neutrophils, changed content of lysosomes, C3b+and Fcγ+-cells against the background of the decreased fraction of active neutrophils and lysozyme in blood, the degree of whose expression is determined by the patient age and the clinical course of the infection.