Abstract: This paper analyses the law of coastal dunes wind erosion/deposition and influencing factors along the Yellow River coast of Ulan Buh Desert. A field observation test about wind erosion and deposition was carried out in Liuguai moving dune of coastal regions of the Yellow River. Results show that:(1) Differences between wind erosion and deposition at different positions of the sand dunes are related to the spatial distribution of the wind speed. In the foot and middle of the windward slope, it's given priority to wind erosion, and wind erosion rate is 1.07 cm·d^-1 and 1.31 cm·d^-1, respectively. In the crest, erosion and deposition occur alternately, and erosion rate is 2.16 cm·d^-1, deposition rate is 1.36 cm·d^-1. Leeward side of the dunes is given priority to deposition by eddy current effect, deposition rate is 2.19 cm·d^-1, and wind erosion occurs only in summer and fall of reverse wind period. The dunes lowland is affected by the upward dunes on the block, and it is given priority to deposition, with deposition rate on average 0.12 cm·d^-1. Net amounts of wind erosion in lowland and leeward side exist significant difference (P<0.05), but the difference is not significant between lowland and the foot of the windward slope, middle windward slope, crest (P>0.1). There is not extremely significant differences between leeward side and foot of the windward slope, middle windward slope, crest (P<0.01). The sand activity intensity is sorted as crest > leeward side > middle windward slope > the foot of windward slope > lowland. (2)There are significant differences in the wind erosion between summer to autumn and winter to spring (P<0.05), and the seasonal difference of wind speed and precipitation are the main factors of wind erosion seasonal differences.

Key words: sand dune, wind erosion rate, erosion pins, Ulan Buh Desert