To investigate the catching efficiency of a biodegradable round trap for a swimming crab (Portunus trituberculatus), four types of material (two types of biodegradable net, one type of biodegradable plus polyethylene net and one type of polyethylene net) for traps were used in the field test, and the field tests were carried out 11 times in the Boryeong fishing ground of Korea, 2012∼2013. The catching efficiency of four type traps was analyzed by catch per trap, weight per trap and mean weight per individual of small and large size swimming crab. Statistical Kruskal-Wallis test was carried out to verify the significant difference for the efficiency between types of material. The catch in number of swimming crab was 9,015 and formed about 94.3% of total catch. In the results of catching efficiency of traps, there was a little difference in catch per trap, weight per trap and mean weight per individual of swimming crab in-situ data. But there was no significant difference in catching efficiency between the biodegradable traps and the PE trap (P>0.05), so it’s needed to use widely a biodegradable trap for the conservation and sustainable management of swimming crab resources.