The dataset comprises contents and mass-accumulation rates of lignin in sediment cores from the Bering Sea (core SO202-18-3/6) and the Okhotsk Sea (cores SO178-13-6). These data have been obtained on these two cores: SO202-18-3/6 for the dry bulk density, sedimentation rate, and sea surface temperatures; lignin phenols concentrations are available for both cores. Moreover, contents of 3,5-dihydroxybenzoic acid are given. Contents are calculated relative to total organic carbon contents and to the dry weight of the sediment.