An experiment to acoustically analyze the shape of gill-net in the current was conducted in Jaran Bay, Gosung, Korea on the 9th to 10th September(spring tide) and 28th to 29th September(neap tide) 2006. It was measured by a 3D underwater positioning system with a radio-acoustic linked positioning buoys. Six of 7 acoustic transmitters used in the experiment were attached on the float line of the gill-net and the other was fixed on the sea bed. During spring tide, the maximum movement of the gill-net was 27.0m(22:00) in the west(4.4cm/s, $311.9^{circ}$) and 20.6m(04:00) in the east(3.9cm/s, $66.5^{circ}$). The maximum extension of the gill-net(the distance between P1 and P6) was 119.8m(21:00, 11.6cm/s, $321.9^{circ}$) and the minimum was 109.9m(23:00, 16.1cm/s, $88.5^{circ}$). During neap tide, the maximum movement was 38.0m(20:00) in the east(9.6cm/s, $278.2^{circ}$) and 11.0m(12:00) in the west(1.9cm/s, $232.1^{circ}$). The maximum extension was 99.6m(14:00, 12.5cm/s, $94.7^{circ}$) and the minimum was 85.0m(06:00, 9.0cm/s, $265.8^{circ}$). During spring tide, the maximum height of the gill-net from the sea bed was 3.7m(02:00, 7.4cm/s, $151.6^{circ}$) and the minimum was produced the three times as 1.5m. At that time, the current speed and direction was 17.9cm/s and $85.3^{circ}$(23:30), 16.1cm/s and $249.4^{circ}$(05:00), and 13.7cm/s and $291.4^{circ}$(06:30), respectively. During neap tide, the maximum height was 3.6m(12:30, 2.1cm/s, $242.3^{circ}$) and the minimum was 1.5m(14:00, 12.5cm/s, $94.7^{circ}$).