[Objective] Studying the windbreak efficiency of shelterbelt in Yudaokou pasture in Bashang Area of Hebei Province to provide a theoretical basis for the construction of pasture shelterbelt.[Methods] Taking The Pinus sylvestris shelterbelt as the research object

the spatial multi-point observation method was applied.[Results] When the desert wind speed was 3.84 m/s

the wind speed was the smallest at 1 H(H stands for the average hight of the forest shelterbelt) after the forest

and the wind efficiency was the most

but with the increase of the horizontal distance

the wind speed was gradually increased and the wind efficiency gradually decreased. The greater of the desert wind speed

the higher of the windbreak efficiency

and the larger of the effective protection distance. When the wind speed level in the open field was 5~6

in the forest

1 H and 5 H of the wind protection efficiency were the best

and the wind efficiency range was 67.97%~94.27%. Windbreak efficiency at diffent vertical heights ranked:30

50

150 and 300 cm

and the rank of wind speed distribution was opposite to that of windbreak.[Conclusion] After the pasture shelterbelt of the 1 H to 10 H area is the best protection area and the action scope of the forest belt. The windbreak efficiency of the post forest 1 H is best

but it will vary with the change of wind speed and vertical height.