Anti-tension and tensilest rength of single root ( the diameter range of roots is between 0.3 and 3 mm) under momentary gale were determined. Plants studied were Caragana microp hylla Lam, Salix psammophila C. Wang et Ch. Y. Yang, Sabina vulgar is Ant., and Artemisia sphaerocephala Krasch., which were 3~ 4 years old. The function of momentary gale was simulated by instantaneous tension. Results show that in the early growth period ( early May) and the vigorous growth period ( mid-August), anti-tension of four kinds of single root shows a positive exponential relation to diameter. The plants, interms of anti-tension and average tensile streng th, are ranged in the order of Caraganami crop hylla Lam> Salixpsammop hila C. Wang et Ch. Y. Yang> Sabina vulgaris Ant.> Ar t emi sia sp haer ocep hala Krasch. Anti-tension and average tensile strength of single root in the early growth period is greater than that in the vigorous growth period except Caragana microphylay Lam.