Caminus jejuensis n. sp was collected from depth of 20 m at Geomeunyeo, Seogwipo, Jejudo Island by a SCUBA diving from April 2004 to December 2008. This new species is similar to C. chinensis from China in the composition of spicules except for the spherasters and they differ in spicule size and growth form. This species has longer orthotriaenes and spherules, smaller sterrasters and oxyasters than those of C. chinensis. This species also has many spherasters in choanosome, but C. chinensis lacks. Morever, the new species is a massive shape with wrinkles, whereas C. chinensis is a club shape with smooth surface. Description and figures of the new species are provided.