The model purse seine was prepared following Tauti’s modeling law and actual cases. The dimensions of the model purse seine were: float line length, 80.9 m; maximum net height, 15.6 m; lead line length, 98 m; basic lead line weight, 0.663 kg/m; and float line buoyancy, 25 N/m. The same hanging ratio was used for the model net and the full-scale purse seine. The results show that the relationship between sinking depth (D) and time (t) for the middle sec- tion of the lead line was described by the formula: D=−0.0014t2 + 0.276t–0.6476 (R²=0.9953). Lead line weight, but not setting speed, had a significant effect on sinking performance, while the interaction effect caused by these two factors was significant on sinking depth. Lead line weight of 0.531–0.663 kg/m increased sinking depth significantly, whereas sinking speed showed a decreasing trend. Lead line weight of 0.663–0.759 kg/m decreased sinking depth slightly, whereas sinking speed improved significantly. A lead line weight of 0.663 kg/m resulted in a tendency that sinking speed increased as setting speed increased. As sinking time increased, tension on the lead line of 0–20 s fluctuations was needed to maintain a steady state. Constructing the mode net is an important part of a model test and is directly related to the model test results. In this study, we constructed a tuna purse seine model to better understand tuna purse seine performance.