In the analysis of samples of planktonic Ostracoda from the northeast of the East China Sea and in the cooperative study on the Kutoshio of China and Japan, we discovered a new species belonging to Paraconchoecia.This specimen being different from other seven species of the "Procera" group in the genus in its having dorsal spines on both shells and other features, is named Poraconchnecia diacanthus n.sp.