By using DNCB delayed hypersensitivity test, the reaction of spontaneous rosette formation (RSRF) and the reaction of inhibition of leucocytes migration the authors examined 55 female patients with different forms of trophoblastic tumors of the uterus and 15 females following the removal of the mole without any signs of the disease concerned. Forty three patients showed a positive DNCB test, 93 of them were completely cured, a negative test was noted in 12 patients, only a 50% cure being observed. RSRF indicated the increased level of rosette-forming cells from 4,7--28% up to 10,3--73% in a successful treatment and its decrease down to 0--5% in the tumor progression, except 7 patients showing reduced RFC levels after the recovery. The reaction of leucocytes migration inhibition has revealed a considerable depression of leucocytes migration (MI--from 0.35 to 0.78) in 18 of 25 patients with manifestations of an acute tumor process (72%). In 7 cases no inhibition was noted, in 6--the treatment being insignificantly effective or time-consuming. In 21 (47.8%) of 27 patients without any signs of the affection there was no inhibitory effect. Leucocytes of healthy donors failed to respond to the tumor extract in either of 24 cases.