Based on located research method

soil organic carbon(SOC) and soil total nitrogen(STN) contents in 0~20 cm(upper) and 20~40 cm(below) soil layer of Betula luminifera-Hemarthria compressa and Pleioblastus amarus-Hemarthria compressa two vegetations were analyzed in the initial(1~7 year) of conversion cropland to forest.The results showed that SOC and STN contents in two layers of B.luminifera-H.compressa and P.amarus-H.compressa two vegetations rapidly decreased in the beginning and subsequently increased with time

those in the upper layer accumulated in the sixth year and the fourth year respectively

but those in the below layer both accumulated in the fifth year.C/N ratio only increased in the second or third year but showed indistinct change in other years.After seven years' vegetation restoration

SOC contents and C/N ratio of P.amarus-H. compressa vegetation were higher than B.luminifera-H.compressa

but the improving condition of soil nitrogen was not obvious.Following the conversion cropland to forest project

the soil carbon and nitrogen content were picking up and appearing sequestration effects despite that they didn't restore the level of cropland.