In this study, the effect of slope length and angle at the entrance to fishing pots on the size of captured shrimp was examined to determine the optimal design of pots for use in Hokkaido, Japan. The purpose of the current study was to optimize the design of shrimp pots to allow greater control over the size of captured individuals for the purposes of shrimp resource management. Tank experiments were conducted to determine the optimal slope length and slope angle by analyzing the sizes of shrimp entering 10 model pots with combinations of five different slope lengths on slope angle of current shrimp pot, and five different angles on slope length of current shrimp pot. The results showed that, as the slope length of the pot increased, the size of individuals which entered the pot increased. In addition, as the slope angle was elevated in each of the five different slope angle treatments, the size of individuals entering was also increased.