Analytical precision of dissolved organic carbon (DOC) in scawater using the high-temperature catalytic method (HTCO) distributions of DOC in the continental margin off northern Taiwan were investigated. The DOC concentration of Kuroshio water off northeastern Taiwan varied from 122-136µM C at the surface to 65-74µM C at the bottom. The concentration decreased sharply downward in the upper 200m of the water column and then decreased slightly toward the bottom. The pattern showed neither seasonal variation nor a significant difference from that observed in the water off southeastern Taiwan. The concentration of DOC was found to be inversely correlated with apparent oxygen utilization (AOU) in the Kuroshio water. The slope, however, was smaller than that predicted from the Redfield stoichiometry, indicating that only a small fraction (<25%) of AOU was derived from the oxidation of DOC. Distributions of DOC were found to vary, both temporally and spatially in the continental shelf and slope waters.