Toxoplasma gondii (T. gondii) is one of the intracellular parasitized protozoa and may cause severe medical complications in fetus or immunocompromised individuals. T. gondii existed as tachyzoite during acute stage while as bradyzoite during chronic phase in human cells. To improve understanding of the prevention, diagnosis, and treatment of the disease, it is important to explore the distribution and fluctuation and other biological features of T. gondii in host. The trophozoite had been found in the saliva, blood or urine of the host.1-4 Some studies suggested the dynamic changes of circulating antibody and toxoplasma circulating antigen (TCA) either in blood or in urine.5,6 T. gondii in tissue or blood cannot be counted exactly under the microscope because it was only several micrometers in size and thus most of the studies were performed qualitatively by mouse inoculation or immunology methods. The quantitative fluorescent polymerase chain reaction (QF-PCR) and its application raised the possibility for dynamic observation of the polypide in the host.7,8 In this study, blood and semen were collected from the male rabbit model infected with toxoplasma tachyzoites and T. gondii was detected by QF-PCR quantitatively.