This paper studied Sophoramoorcro f tiana population by establishing two plots(20 m × 30 m)on semi-fixed and fixed sandy lands in the middle reaches of the Yarlung Zangbo river.The height and diameter at basic height(DBH)of each individual tree in each community were measured

and life history was charac- terized using DBH class structure

static life table

survival curves.The results showed that the DBH class structures of Sophora moorcrof tiana on the semi-fixed sandy land and fixed sandy land were similar

being broad at the base and narrow at the top with the individual numbers reduced as the DBH classincreases.Sophora moorcrof tiana population structure belonged to the growing type on the semi-fixed sandy land and approached mature type on the fixed sandy land.The seedlings of Sophora moorcro f tiana had high mortality rate

while the adult trees had lower mortality rate

with the survivorship curve following the Deevey TypeⅡ.