The main goal of this project is monitoring of the species and theconcentration distribution of organic tin compounds in seawaters, sediments, and fishes nearby the Kenting coastal area. Gas chromatography/flame photometric detector (GC/FPD) was used to analyze organic tin compounds in samples.Results of this study showed that the average concentration of MMT in surface waters ranged from 4.59 to 21.35ng/L, in bottom waters ranged from 10.07 to 23.63ng/L, in sediments ranged from 2.98 to 17.95ng/g dry wt. The average concentration of MBT in surface waters ranged from 0.13 to 3.25ng/L, in bottom waters ranged from ND to 1.03ng/L, in sediments ranged from 0.03 to 0.68ng/g dry wt. The average concentration of DBT in surface waters ranged from 1.10 to 3.98ng/L, in bottom waters ranged from 1.77 to 5.60ng/L, in sediments ranged from 0.53 to 4.38ng/g dry wt. The average concentration of TBT in surface waters ranged from 0.13 to 0.73ng/L, in bottom waters ranged from ND to 1.53ng/L, in sediments ranged from 0.25 to 2.48ng/g dry wt. The concentration of MMT was much higher than other organic tin compounds. No phenyl-tin compounds were detected.In the tissues of fish, the concentrations of organic tin compounds in liver and kidney were higher than those in other tissues. The ratio of TBT to DBT and MBT in muscle tissues was higher than those in liver and kidney tissues. In general , no serious contamination of organic tin compound was observed nearby the Kenting coastal area.