The jumping ability of Reeves's muntjacs (Muntiacus reevesi) was experimentally determined and verified in a captive environment using seven male animals. The experiment found that the maximum height that Reeves's muntjac could jump over was 80 cm. Against an obstacle of 45 cm or more, the latency to jump and the time spent on exploratory behavior were longer relative to lower obstacles. Based on this result, net fences with a height of 85 cm were installed at three sites in Isumi City, Chiba Prefecture, Japan, and bait was installed inside the fence to verify its intrusion prevention effect. For over a month, even in winter when food resources are scarce, the muntjacs did not jump over the fence to reach the bait. However, during the first week of the test session, physical contact such as pressing the head and nose against the fence was observed, and exploratory behavior was concentrated on the base of the fence. These results suggested that a high intrusion prevention effect could be obtained by installing a fence with a height of 85 cm and securing the fence hem with piles.