To assess and monitor the degree of marine pollution, the sediment samples were collected in Yellow Sea and Kwangyang bay and conducted bioassay and analysis for the physical/ chemical environmental parameters. Sea urchin (Hemicentrotus pulcherrimus) embryo bioassay was conducted in order to evaluate and map the pollution station of sea sediments. The results were shown a severe inhibitory effect on the embryo bioassay of sediments collected in Kwangyang bay as compared with Yellow Sea. The correlationships between the embryos and the environmental parameters (COD, ammonia, nitrite level) were investigated by simple correlation analysis. After insemination, the correlation coefficient value (r) on the normal embryos observed at 48 hours (-0.8321) was the highest in ammonia level but very low values in COD, Nitrite.