From the early to the late Western Han dynasty (206B.C. 9A.D.), the ingate shape and mold cavity arrangement used in the bunchcasting of bronze coins underwent change. In this paper, computer simulated casting processes were used to study the effect of ingate shape and mold cavity on mold filling and solidification. The results showed the following:1) The mold cavity arrangement has little impact on the mold filling time. 2) The design inside the mold has an effect on the molding process:when the inner mold is straight in the middle, it is likely to cause air bubble and other defects. 3) The ingate shape influences both the mold filling process and mold filling time, but has little effect on the solidification process, with regard to the coin''s shape. From the middle to the late Western Han Dynasty, an oblique inner mold was commonly used, suggesting that the Han Dynasty technician already understood the effect of the inner mold on the molding process, and therefore could selectively choose a better inner mold design. During the coin molding process, a shortened filling time is desired, preliminary to the molding process. Since the middle of the Western Han Dynasty, an inner mold that had a shorter filling time was commonly used to increase the filling capability, and meanwhile, increased qualification yield.