Abstract: Tensile test is carried out on the Sabina vulgaris Ant.'s root in Zhangjiakou city, the results show that with the increase of diameter, the anti-tensile strength of single root increases in the form of power function, and the tensile strength of single root decreases with the increase of root diameter, and the correlation coefficient is higher. The root with large root diameter has limited reinforcement effect on slope soil, while the root with small root diameter has greater tensile strength, which plays a major role in root slope protection. The elongation rate and sectional shrinkage of single root decreases in the form of a straight line with the increase of the diameter, and the correlation coefficients is high.The root diameter is smaller, and the root elongation is larger, which reflect from the side that the toughness decreased with the increase of the root diameter. The diameter of the root is 1.00~6.00 mm, the anti-tensile strength is 25.0~369.0 N, the tensile strength is 13.00~17.00 MPa, the elongation rate is 8.00%~12.00%, the sectional shrinkage rate is 8.00%~12.00%, the average anti-tensile strength is about 170.7 N, the average tensile strength is 14.89 MPa, the average root elongation is 10.76%, the average section shrinkage is 9.82%.

Key words: Sabina vulgaris Ant., anti-tensile strength, tensile strength, elongation rate, sectional shrinkage, ecological slope protection