The dataset comprises contents and mass-accumulation rates of lignin phenols in sediment cores from the Bering Sea (cores SO202/1_18-3 and SO202/1_18-6). Eight lignin-derived phenols were analyzed in our study. They can be classified into three groups according to their plant sources and structures: Vanillyl phenols (V) consisting of vanillin (Vl), acetovanillone (Vn) and vanillic acid (Vd). 2. Syringyl phenols (S), comprising syringealdehyde (Sl), acetosyringone (Sn) and syringic acid (Sd). 3. Cinnamyl phenols (C) that include p-coumaric acid (p-Cd) and ferulic acid (Fd). Besides, we also included some other oxidation products that do not necessarily originate from lignin, such as 3,5-dihydroxybenzoic acid (3,5Bd). Contents are calculated relative to total organic carbon contents and to the dry weight of the sediment. Indicators for vegetation development (S/V and C/V), wetland extent (3,5Bd/V) and degree of organic matter degradation ((Ad/Al)s and (Ad/Al)v) are given. Moreover, TOC and dry bulk density of the two sediment cores are also shown in this dataset.