To understand nonylphenol (NP) contamination in the northeast coastal environment in China,NP was determined in 19 sediment and 20 bivalve samples collected during November 2005.NP was identified in all sediment samples in the range of 8.8 to 1.0×103 ng/g dw (dry weight),with an average of 0.12×103 ng/g dw.Most of the bivalve samples (oysters and mussels) contained detectable amounts of NP that ranged from ND (not detected) to 7.6×103 ng/g dw,with an average value of 0.79×103 ng/g dw.These results indicated that NP is ubiquitous in sediments and bivalves from the northeast coast of China,and are even present in bivalves sold as seafood.Serious contamination with NP was recorded off the coast of Bohai Strait and in semi-enclosed coastal environment such as Jiaozhou Bay and Liaodong Bay.Possible environmental and human health implications were understood in this study.