Abstract: In order to reveal the vertical distribution of dust over different underlying surfaces in the Ulan Buh Desert in winter, the sediment discharge of 3 kinds of underlying surfaces were analyzed based on the actual monitoring data in winter. The total sediment discharge of 0-100 cm height in winter was mobile dune > fixed dune > semi-fixed sand dune. The sediment discharge over 3 kinds of underlying surfaces all decreased with height and conformed to power function distribution. The sediment discharges over mobile dune, fixed dune were concentrated in 0-20 cm height and the sediment discharge over semi-fixed sand dune was mainly concentrated in 0-40 cm height. The coefficients a and b was negatively correlated with the concentration of < 0.1 mm particles and >0.5 mm particles, and was positively correlated with the concentration of 0.1-0.25 mm particles, and no correlation with the concentration of 0.25-0.5 mm particles. The saltation heights over mobile dune, fixed dune and semi-fixed sand dune were 3.59 cm, 2.36 cm and 4.33 cm, respectively. There was a positive correlation between the saltation height and the concentrations of <0.05 mm and 0.1-0.5 mm particles, especially there was an exponential function relationship with the concentrations of 0.1-0.25 mm particles, but there was no significant relationship with the concentrations of 0.05~0.1 mm and >0.5 mm particles. The mobile dune in the Ulan Buh Desert was still in serious erosion in winter, and semi-fixed sand dune was basically stable, and fixed dune was in the accumulation state. Fixed dune was still play a role in sand fixation in winter.

Key words: sediment, underlying surface, correlation, the coefficient of sand flow