In order to develop the biodegradable monofilament gill net for the protection of marine ecosystem and reduction of ghost fishing, enpol monofilament gill net was made for Chionoecetes opilio using polybutylene succinate as a biodegradable chip. Catching efficiency on 2 type monofilament gill net, PA and Enpol, were carried out using 2 commercial fishing boats around the fishing ground of Wang-dol rock from January 2004 to May 2006. Enpol monofilament gill net spun polybutylene succinate as a biodegradable chip was appeared high practicality for Chionoecetes opilio gill net. Target fishing ratio were 98% and 98.3% for the PA and enpol monfilament gill net, respectively. In addition, CPUE ratio of female and male(CL < 90mm) to Chionoecetes opilio caught in the enpol gill net were 25.3-40.3%, 14.0-22.1% less than PA gill net, respectively. However, CPUE ratio of male(CL > 90mm) to Chionoecetes opilio caught in the enpol gill net were 2.5-11.3% more than PA gill net. There was no difference in CPUE of female and male to Chionoecetes opilio caught using 2 gill nets as a result of the significance level of 5% by T-test.