The Siberian rivers discharge huge amounts of freshwater and terrestrial material into the Arctic Ocean. Investigations on lignin, elemental and stable carbon isotope compositions of dissolved, particulate and sedimentary organic matter were conducted in view of the carbon cycles and of the potential use as tracers for terrestrial material and water masses in the Arctic Ocean. The rivers investigated discharge 43% of the total fresh water discharge to the Arctic Ocean. Samples from 12 Siberian rivers along 4000 km of coastline as well as from different regions of the Arctic Ocean were analysed. Particulate organic matter (POM) transported by rivers, which drain Taiga regions, originated from C3 plant material consisting of gymnosperm wood with portions of non-woody tissues as shown by its stable carbon and lignin compositions. POM from Tundra regions also stemmed from C3 plants but compared to the Taiga material a higher contribution of non-woody and angiosperm tissues was found. The carbon / nitrogen ratio showed values typical for soil. The contribution of C4 plants as well as phytoplankton and zooplankton to the particulate material was negligible. Concentrations of dissolved organic matter (DOM) exceeded those of POM five times. The lignin composition of DOM was similar compared to POM but showed a higher degree of degradation. The export rate of organic material depends primarily on the net primary production which differs considerably between the vegetation zones. The carbon export rates of the Tundra rivers ranged from 1.5 to 3.8 g C m-2yr-1 whereas rivers which drain mainly Taiga areas showed a higher variability with rates between 0.03 and 5 g C m-2yr-1. The signature of organic material changed dramatically when entering the Arctic Ocean. Terrestrial DOM dilutes conservative in the upper Arctic water layer as indicated by its lignin concentrations and C/N ratios. The allocation of DOM to its marine and terrestrial sources fits well to the in situ production rates for the Arctic Ocean as recently reported by other authors. In contrast most of the terrestrial POM got lost in the river mouthes. This low contribution of terrestrial POM to the Arctic Ocean is also found in sediments. Lignin determination revealed that in slope and deep sea sediments the terrestrial organic matter is less than 1%. Differences in lignin compositions are found in the sediments which enable the accessment of terrestrial material to different rivers.