The paper studies on the nutrient distribution and accumulation pattern of the Castanca mollissima B1 forest in north Beijing mountain area. Its results show that the total biomass of the Castanca mollissima Bl stand at age 22 in the experimental area is 38 638 kg/hm~2

and it distributed in stem

branch

leaf

blossom

chestnut

seed capsule and root biomass are 20 160 kg/hm~2

8 430 kg/hm~2

1 429 kg/hm~2

873 kg/hm~2

1 024 kg/hm~2

800 kg/hm~2 and 5 922 kg/hm~2

respectively. It's occupying 52.18%

21.82%

3.70%

2.26%

2.65%

(2.07)%

15.33% of total biomass

respectively. The five nutrient elements N

P

K

Ca

Mg accumulated in stand crop is 315.38 kg/hm~2

and different nutrient element storage amount greatly varied in the different organs of the Castanca mollissima B1 forests. The sequence of five nutrient elements storage of different organs are follows: truck>branch>root> leaf>flower>seed capsule>chestnut. The five nutrient elements total storage in depth from 0 to 30 cm of the soil is 206 427.59 kg/hm~2

and available nutrient is 16 618.29 kg/hm~2

the crop nutrient elements storage amount just is occupying about 0.15% of the total nutrient store in the soil of five kind nutrient elements

and 1.95% of the available nutrient store in the soil of five kind nutrient elements. And the sequence of enrichment coefficient of the five elements are follows: N>P>K>Ca>Mg. The net production of organic of forest per ton needs a total five elements of 7.17 kg

and the Ca element amount is the biggest

and the P is the smallest among the five nutrient elements.