Kaohsiung Harbor is the largest international sea port in Taiwan, a lot of ships around the world pass in and out frequently, the pollution of organotin is very serious in the harbor area. Love River and Chien-Chen River may be polluted by the seawater tidal action from the Kaohsiung harbor. Domestic, industrial and agricultural wastewaters discharged into the upstream sections may also cause the pollution of organotin. The purposes of this study were to understand sources of organotin pollution by analying the content of organotin compounds and to monitor the organotin pollution of the rivers in Kaohsiung. Samples including surface sediments and riverwaters were collected from nineteen stations of Love River and Chien-Chen River. The results revealed that concentrations of MBT, DBT and TBT in the riverwaters of Love River varied between 13.4-43.6, 2.6-9.9 and ND-13.5 ng/L as tin. The concentrations of MBT, DBT and TBT in the riverwaters of Chien-Chen River were 3.1-28.1, 2.1-10.9 and ND-9.1 ng/L as tin, respectively. The concentrations of MBT, DBT and TBT in the surface sediments of Love River varied between 20.6-92.3, 7.6-26.2 and ND-15.4 ng/g as tin. The concentrations of MBT, DBT and TBT in the surface sediments of Chien-Chen River were in the range of 22.4-70.0, 6.4-14.1, ND-31.9 ng/g as tin, respectively. MBT and DBT were detected in all the samples of all the sampling stations of Love River and Chien-Chen River. Distribution of organotin compounds in riverwaters and surface sediments showed a consistency between these two rivers. No phenyltin pollution was detected at all stations, probably due to the decline in agricultural activities and the ban on utilizing triphenyltin acetate as pesticide. Except the highest organotin pollution appeared in the outfall of Love River and Chien-Chen River, other high values of pollution were found near the upper reaches of both rivers.