Tributyltin (TBT) and its degradation products, dibutyltin (DBT) and monobutyltin (MBT), in the commercial sea products collected from seven Chinese cities were measured to evaluate the extent of contamination and the potential adverse effect on health. Universal existence of butyltins was found in these samples, and the concentrations of TBT ranged from <6.9 to 17175 ng of Sn g(-1) of wet weight. The accumulation ratios of the pollutant in these organisms were as high as 10(3) or more compared with the previously reported data in corresponding water. The existing different accumulation capabilities of pollutants among the various seafood species were studied. It was observed that the butyltin compounds were comparatively stable during cooking or processing procedures in the manner of usual Chinese cooking way. The occurrence of butyltin compounds in sea products indicated a potential danger for the health of people who consumed seafood in these areas.