The variation features of soil- plant system in the natural restoration processes of deg raded sandy grassland in the Horqin sandy land af ter 5 years of exclusive grazing by a nimals are studied.In the mea ntime

the interacting deg ree between soil properties and plant cha racteristics are analyzed.The result s show that: (1) As moving sand was turned into fixed sandy land

the species diversity in plant communities

vegetatio n cov er

underg round root volume and surface litter residue tended to increase.The measured values of β diversity demo nst ra te tha t as semi fluid sand was restored to semi fixed sand

The turnover rate of plants increased and the chang es in plant community structure became evident.(2) In the natural restoration processes of degraded sandy grassland

the structure of surface soil layer significantly improved and the availability of soil nutrients correspondingly enhanced.(3) Correlation analy ses show that there is a close correlation between to psoil physiochemical properties and plant cha racteristic values of the sandy grassland.This shows that the restoration processes of degraded sandy grassla nd are virtually a synergi stically evolutional processes of soil-plant system

the key restoration phase of plant diversity lags behind the key restoration phase of soil environment in the processes.