Marine environment has been seriously polluted by organotin compounds (OTCs) due to their wide application in catalysts, antifouling paints and stabilizers. The high toxicity of organotin compounds has been of great concern for their severe impacts on non-target marine organisms. Ascertaining the status of pollution timely and accurately would be helpful to the protection and management of marine environment. The tanglesome pretreatment procedures needed for many complicated environmental samples may be lead to the error of the research results. However, the preparation of reference materials will give a support of assuring the accuracy of the results. A research has been carried out for the pollution of organotin compounds in surface sediments from selected Chinese coastal fishing ports and Pearl River Estuary. The results showed that butyltin compounds (BTs) were the main species in the sediments from selected fishing ports. The concentrations of monobutytin (MBT) compounds were higher than those of dibutyltin (DBT) and tributyltin (TBT) compounds. The concentrations of OTCs in the sediments varied widely among different sampling locations with much higher butyltin levels at fishing ports close to the South China Sea. MPhT was prevalent in most fishing ports except for those in coast of the East China Sea. BTs were also the main species in the sediments from Pearl River Estuary. The concentrations of BTs have a good relationship with the accumulation of sediments. TBT was mainly found on the navigation channels. Antifouling paints are the main source. MBT and DBT were predominant species in the east coastal area. It was assumed that the MBT and DBT were come from antifouling paints and terrestrial runoff. Although OTCs were detected in the selected areas with high detected frequency, the relatively lower concentrations showed low environmental and ecotoxicological risks. BTs including MBT, DBT and TBT, were determined in mollusks collected from the Chinese Bohai coastal cities in 2007, 2009-2011. BTs compounds were widely existed in the collected samples, with the ranges from <1.1 to 765.0 ng Sn g-1 dry weight. The concentrations of BTs in mollusks varied widely among different locations. The concentrations of BTs in mollusks from Weihai, Tianjin, Yantai, Beidaihe and Huludao were much higher than those from Shouguang, Penglai, Yingkou and Dalian. Bioaccumulation of BTs varied strongly among different organisms. The concentrations of BTs in oysters and Mya arenaria were obviously higher than those in other species. A tendency of decomposition for TBT was observed. The new biological reference material, Mya arenaria, for analysis of BTs prepared by our lab was assessed. DBT and TBT showed good homogeneity and stability in one year at 300 mg levels of intakes. However, the homogeneity in a -test and the stability in a t-test for MBT were unsatisfactory. The reason of instability for MBT would be further analyzed. The certified values of BTs were obtained by the combination of three various certified methods. And the uncertainties of the certified values were calculated through traceability analysis. This new material will be of great support to ensure the quality control of butyltin determination in mollusk, as carried out in environmental monitoring programmes.