Abstract: It has been studied some development features of parthenogenetic and dioecious generations of Schistosoma turkestaniсum trematodes – mammal parasite of Uzbekistan. It was identified that in experimental infestation of Lymnaea (=Radix) auricularia mollusks trematodes miracidia at temperature 28-30 0С formation of cercaria occurs within 20-22 days. Formed cercaria leave the mollusk-host organism in 22-25 days. The cercaria life period in water about 72 hours. The cercarias penetrate actively into the organism of final host within short time. It is enough 5-10 minutes of cercaria contact with host body to their implantation throw the animal skin. Schistosoma attains virility and begin to reproduce in the organism of rabbits, sheep and cattle. Maturity periods of males and females are 32-35 days. Essentially, they are localized in veins of mesentary and liver. Mature eggs of parasite is discovered in feces of animals in 45-50 days after infestation, i.e. in 10-15 days after attain virility of parasite. Schistosoma life duration in organisms of definitive hosts is more than 10 years in cattle, 8 years in sheep, 3.5 years in rabbit. Practically, schistosoma may parasite their hosts up to death. Original data given on the features of morphology and biology of all phases of Sch. Turkestaniсum development and their meanings in taxonomy have been given. Data on a new find of this species in wild animals have been presented as well (hare, saiga, Bukhara deer and gazelles).