Abstract: The experiment was conducted on the morphological and biomass spatial distribution characters of the annual psammophilous Bassia dasyphylla in Minshazui of Gulang County in Gansu. The results showed that the crown, ground diameter, root depth, root range, lateral root number and length all had very significant linear positive correlations with plant height(P＜0.01) , the degree of correlations between aboveground morphological index and height was higher than the underground. The tress had more ramification, the number of first order ramification was 30.40, the secondary ramification reached 260.87. The average single biomass of B. dasyphylla was 74.21 g, the aboveground part was 67.83 g, and the underground part was 7.38 g.The aboveground biomass concentrated in 1030 cm, this layer occupied 77.64% of aboveground part, the components according with the size of biomass in order as tress, fruit, leaf. The underground part biomass concentrated in 010 cm, this layer occupied 76.29% of underground part, and lateral root was more developed than main root. Differences of fresh and dry biomass of components in different layers were basically similar, the differences of 1020 cm and 2030 cm compared with 3040 cm and 4050 cm of aboveground were significant, the differences of 010 cm compared with 1020 cm and 2030 cm of underground were significant, however, there was no significant difference in other different layers.