An examination is made of the helical geometry effect on the tritium breeding in the Heliotron reactor blanket. Calculations are performed with the three-dimensional Monte Carlo code MORSE-I for the cylindrical, torus and helical geometry models, each approximating the configuration of the Heliotron reactor in various degrees. A comparison of the tritium breeding ratios obtained between these models indicates that the helical geometry effects would be modest. However, it is found that there exists neutron streaming through between blanket regions, due to the helical geometry of the system.