Ocean-derived dimethyl sulfide (DMS) has been widely concerned because of its hypothesized significant influence on global climate change. High-resolution shipboard underway measurements of DMS and partial pressure of carbon dioxide (pCO₂) in the surface seawater and atmospheric were conducted from the marginal sea to the Northwest Pacific Ocean in November 2019. Atmospheric and surface seawater DMS concentrations ranged from 19 to 122 pptv and from 0.4 to 1.8 nmol L^-1, respectively, with the mean values of 44 ± 19 pptv and 1.1 ± 0.34 nmol L^-1. The average sea surface pCO₂ was 370 ± 16 μatm (range:332 to 401 μatm). The variations in DMS of surface seawater in the Northwest Pacific Ocean were primarily associated with the phytoplankton biomass and community under different current systems. The biological activities and physical processes such as cooling jointly influenced the changes in sea surface pCO₂. The cold eddy on the track in the Northwest Pacific Ocean can increase DMS at the sea surface by 10% and CO₂ uptake by 3%. We found a significant negative correlation between DMS and pCO₂ in the Northwest Pacific Ocean using 0.1° resolution, [DMS] _seawater = -0.0161[pCO₂] _seawater + 7.046 (R² = 0.569, p < 0.01). The DMS and pCO₂ sea-air fluxes were estimated to be from 0.04 to 25.8 μmol m^-2·d^-1 and from -27.0 to 4.22 mmol m^-2·d^-1 over the entire cruise. The Northwest Pacific Ocean, especially the Oyashio Current, is an important sink of CO₂ and a source of DMS.