Abstract:We conducted a case study to examine the soil nutrients content and grain size fraction of different aeolian sandy land types in the Shannan wide valley area, middle reaches of the Yarlung Zangbo River by choosing moving sandy land, flat sandy gravel land, semi-fixed sandy land, fixed sandy land and sandy land on flood plain as sample plots. The mechanism how aeolian sand movement affects soil grain size fraction and nutrients content of aeolian sandy land was discussed based on field sand movement observation and wind velocity and direction data from 1980 to 2006 from the Lhasa Airport meteorological station. The results showed that 1) The soil pH value of aeolian sandy land in the study area was neutral, alkaline or strong alkaline, and soil organic matter (SOM) and total nitrogen (TN) content were rather low, whereas total phosphorus (TP) and total potassium (TK) were very high. The soil grain size fraction followed the order of sand content (53.83%-95.93%)> silt content (3.3%-40.5%)> clay content (0.77%-5.68%), and the clay and silt content both presented rather low. 2) The clay and silt content was highest in sandy land on flood plain (4.02% and 27.95%, respectively), whereas that was lowest in semi-fixed sandy land (1.35% and 5.27%, respectively). The clay content in different aeolian sandy land types followed the order of sandy land on flood plain> fixed sandy land (2.98%) > moving sandy land on flood plain (2.89%)> flat sandy gravel land (1.69%)> moving sandy land on river bank (1.54%) > moving sandy land on hill-slope (1.49%) > semi-fixed sandy land. The order of silt content in different aeolian sandy land types was similar with that of clay content except for moving sandy land on river bank and moving sandy land on hill-slope. The sand content was highest in semi-fixed sandy land (93.40%), whereas it was lowest in sandy land on flood plain (68.05%), and the order of sand content in different aeolian sandy land types was just in contrast to that of silt content. 3) The correlation between different soil nutrients and the content of clay, silt, very fine sand, fine sand was strong, whereas the correlation was negative or weak between different soil nutrients and the content of medium sand, coarse sand, very coarse sand. The clay and fine sand content made larger contribution to the soil nutrients content. The aeolian sand movement, which caused the continuous swing of moving sand dunes and the migration and loss of the finer sand particles, affected the soil nutrients content and their redistribution process for different aeolian sandy land types greatly. The purpose of this study is to characterize the soil nutrients content and grain size fraction of different aeolian sandy land types, and to provide a scientific basis for the ongoing vegetation restoration that is being carried out for aeolian sandy land control.