To investigate parasite-host dynamics in cultures of Toxoplasma gondii (T. gondii).T. gondii tachyzoites were incubated in Vero-E6 cell cultures at 37°C, 5％CO₂. Tachyzoites and host cells were characterized by light microscopy. Growth kinetics of the parasite were determined.Doubling time of tachyzoites and viability of host cells were determined by comparing tachyzoite cultures and control Vero cell cultures that were free of parasites. Tachyzoites harvested from cell cultures were established as a line for future studies. Purified tachyzoit line was named as GPK-001, a catalog name for the line.In this study, we showed that an intracellular parasite, T. gondii can be produced in cell cultures under sterile conditions. We believe that the tachyzoite line established in this study would be useful in many other studies and provide answers to questions regarding biology and treatment of T. gondii infections.