Objective To evaluate the biomechanical properties of a modified Herbert screw as a suture anchor in repairing patellar ligament. Method 1) twenty-two fresh goat knee joints were divided into two groups: screw and suture group. All patellar ligaments were cut at the site 6mm proximal to tibia tuberosity. In the screw group, modified Herbert screw acted as a suture anchor in repairing the patellar ligament. In the suture group, patellar ligament was simply sutured according the Kessler method. Tensile force at failure and maximum tensile force were measured. 2)twenty-two hind legs of 11 hybrid canines were divided into two groups: screw and suture group. The patellar ligaments were treated respectively as mentioned before. 4 weeks after operation, the patellar ligaments were inspected and measured. Result 1) For goat knee joints, the average tensile force at failure was (71.13±14.23) N in the screw group and (46.09±8.41) N in the suture group, respectively (P<0.05). The average maximum tensile force was (80.46±11.73) N in screw group, (54.60± 9.79)N in suture group, (P<0.05).2) There were 5 cases in the screw group of canine showed complete healing of the patellar ligament while there were 2 cases shown in the suture group. The average tensile force at failure was (202.99±12.17) N in the screw group and (162.41±15.80) N in the suture group (P<0.05). The average maximum tensile force was (219.69±15.73) N in the screw group and(177.92±15.31)N in the suture group(P<0.05). Conclusions The modified Herbert screw as a suture anchor was a good choice for repairing the torn ligament near its insertion.