Organic complexation of Cu controls the toxicity and bioavailability of Cu for marine microorganism. Therefore, it is important to reveal the speciation and bioavailability of Cu in the ocean. In this study, we determined the concentrations of Cu and its organic ligands in the soluble (＜ 0.03 µm) and dissolved (＜ 0.2 µm) phases in the western (CL-2), central (CL-5) and eastern (CL-16) part of the subarctic North Pacific during the GEOTRACES-Japan cruise GP02 in summer 2017.Concentrations of total dissolved and soluble Cu ranged from 1.28 nM – 4.82 nM, and 0.47 nM – 2.75 nM, respectively. At both CL-2 and CL-16, soluble Cu accounted for 30%-100% of total dissolved Cu. The proportion of the soluble Cu fraction was low in surface waters, increased to maximum in the intermediate waters, and decreased slightly in deep waters. Up to two classes of organic ligands were detected in the surface and intermediate waters, and only one class of ligand was detected in deep waters. Concentrations of the stronger ligands (L1) and weaker ligands (L2) ranged from 1.02 nM – 2.95 nM, and 0.77 nM – 8.78 nM, respectively. The distribution of L1 followed closely that of total dissolved Cu in the surface waters, but no clear trend was observed in the intermediate waters. At CL-2, L1 mainly existed in the soluble phase, whereas for CL-16, soluble L1 accounted for 50% - 100% of total dissolved L1. Concentrations of L2 were relatively constant throughout the water column but elevated concentrations were detected in the surface waters of CL-5 and in the surface and intermediate waters of CL-16. On the other hand, there was a slight depletion of L2 in the intermediate waters of CL-2.