In order to hold the behavior of fish school to the set-net, a series of tag-recapture experiments were carried out in two fishing grounds of the middle sized set-nets which were located in 20m depth on the coast of Keojedo and Namhaedo in the Southern part of Korea from September to October in 1996. In the experiments, the leading ability of the leader and the fish court and the recapturing ability of the bag nets were checked out for the six species of fish in method of discharging the tagged fishes at side points of leader, and the middle points of the fish court and the bag nets in a hauling step, and recapturing them at the bag nets in the next hauling. The results obtained are as follows; 1. The ratio recaptured at the both side bag-nets in the next hauling after discharged from the fish court in the previous step was 20.3% in small size of mackerel Scomber japonicus, 16.2% in small size of horse mackerel Trachurus japonicus, 10.3% in black sea-bream Acanthopagrus schlegelii, 19.1% in red barracuda Syhyraena pinguis, 16.3% in halfbeak Hemiramphus sajori, 20.0% in gizzard shad Konosirus punctatus individually, and totally in six species of fish, that was 17.2%. 2. The ratio recaptured at the same bag net after discharged in the both side bag-nets was 21.7% in small size of mackerel, 21.5% in small size of horse mackerel, 6.7% in black sea-bream, 17.8% in red barracuda, 16.8 in half-beak, 19.1% in gizzard shad individually, and totally in six species of fish, that was 18.8%. 3. The leading ratio from side points of the leader departed from door in 25m to fish court was 58.9% in small size of mackerel, 74.6% in small size of horse mackerel, 38.0% in black sea-bream, 54.7% in red barracuda, 58.6% in half-beak, 54.5% in gizzard shad individually, and totally in six species of fish, that was 57.8%. So it was assumed that the leader of set-net was very effective in leading to the swimming direction of small size of mackerel, small size of horse mackerel, red barracuda, half-beak and gizzard shad. 4. Red barracuda, half-beak and gizzard shad entered into bag net of upstream in large numbers than bag net of downstream, and small size of horse mackerel and black sea-bream entered into bag net of downstream in large numbers than bag net of upstream. 5. Small size of mackerel and small size of horse mackerel had high remaining rate in the bag net of downstream, and black sea-bream, red barracuda and half-beak had high remaining rate in the bag net of upstream.