This research is to numerically perform the optimal design of the shutter valves in the two-stroke engine by analyzing flow resistance with four different design shapes. Shutter valves were numerically analysed for four different industry-design based cases using ANSYS FLUENT V.14. At the result, it was found that the most design-effective case was case 4 with dimensions of 4.5 cm radius and 26 cm length of cylinder with a sphere of 6 cm radius in the valve. Pressure loss of three cases is between 0.70% and 6.48% when compared to case 1. However, 0.16% of pressure loss increased as the rotational speed of valve increased with 1 rad/s. Thus, at lower rotational speed, the case 4 was possibly optimal shape design due to the lowest pressure loss.