Abstract: This paper studies the characteristics of wind shear in flat terrain over Shandong,Jiangsu and Henan,which include the tendency of wind shear exponent varying with heights,hours and months. By analyzing measured data of several towers up to the height of 150 m,it is found that the wind shear exponent varies at different areas,and exposes different characteristics. Namely,the wind shear exponent is minimum at the height of 150 m,changes gently between the heights of 100 m and 150 m,and drops sharply at the height of 130 m. In terms of hourly variation,the wind shear exponent maintains at a relatively low value at the daytime,while it increases to a high value at night and nearly morning,and this tendency is especially evident at the height below 100 m. Furthermore,the wind shear exponent above 100 m varies disorderly with the months,but below 100 m it presents a gradual and fluctuationg increose.