We investigated the seawater methanol abundance, the dynamic of microbial methanol (MeOH) metabolism and the geochemical parameters in the northwest Pacific Ocean (NWPO) area. Seawater samples were collected during May-June 2021 aboard the R/V “Dongfanghong 3” in the northwest Pacific Ocean. Seawater was sampled using a Seabird 911 CTD-Niskin rosette system equipped with conductivity, temperature and depth sensors. Methanol samples were collected directly without filters and then stored at -80℃ for laboratory analysis. Methanol concentrations were determined by a modified commercial purge and trap system combined with Agilent GC-8890 gas chromatograph with a flame ionization detector. Microbial methanol assimilation and oxidation rates were determined by quantifying 14C-MeOH incorporation into biomass and oxidation to CO2 (Zhuang et al., 2018). Nutrients were measured using Seal Analytical Quaatro nutrient autoanalyzer except for ammonium which was analyzed by a fluorometric method on board (Ning et al., 2013). Chlorophyll-a was measured by fluorometric method (Parsons et al., 1984).