The K-OC of three triazine herbicides (atrazine, hexazinone and terbuthylazine) and two triazine degradation products (deethylatrazine and deisopropylatrazine) were derived both by using a HPLC-reversed phase chromatography method and measuring the K-D with sorption isotherms. 21 reference substances and 3 different chromatographic conditions were used to measure the K-OC with the HPLC method. The K-OC values from sorption isotherms were determined using 6 different soils. The two different K-OC values for atrazine, deethylatrazine, deisopropylatrazine and hexazinone derived from the two methods were similar, while those of terbuthylazine were more different. Deethylatrazine, deisopropylatrazine and hexazinone had very low K-OC values, even lower than that of atrazine, and this indicates their tendency to move through the soil