Squid by-product like viscera has just been recognized as one of the serious pollutants on the surrounding marine environment in Ulleung island of Korea. The effect as a marine pollutant, however, has not been examined and evaluated properly. It was carried out the comprehensive examination of the marine pollution by disposing squid by-products. The sediments and water qualities were investigated in several positions, including the dumping position around Ulleung island. It is also estimated a spreading of by-product in terms of estimating the sinking speed and evaluating the attracting characteristics as a feed. As a result, There were no significant pollutions of the sediment and water quality. The spreading of by-product by the local current was 2-2.5 times of the depth, and it will become longer in spring tide. It was confirmed that the squid by-product has attracting ability for local fish by acoustical survey. Furthermore, it can be useful for the local fish species as feeds.