Abstract: The study with compartment model on the phosphorus (P) and sulphur (S) bio-cycling in alpine tundra ecosystem of Changbai Mountains showed that the total storage of P and S was 16088.6 t and 26079.4 t,of which,46.14 t and 64.82 t was in vegetation pool,89.63 t and 53.16 t in litterfall pool,and 15952.8 t and 26 014.6 t in soil pool,respectively.The above?and below-ground vegetation pool stored 21.88 t and 44.21 t,and 24.28 t and 20.61 t of P and S,respectively, and the above-ground vegetation pool had 47.4% of P and 68.2% of S in the vegetation subsystem.The transferable P amount was 24.25 t·yr^-1 through plant absorption and 31.59 t·yr^-1 through litterfall return,while the transferable S amount was 31.18 t·yr^-1,10.12 t·yr^-1 and 21.06 t·yr^-1 in the above-ground plant, below-ground root system,and litterfall return, respectively. The natural return ratio of S was 67.5%.

Key words: Soybean, Ecological regions, Ecological types