Objective To investigate the feasibility and reproducibility of Acoustic Radiation Force Impulse (ARFI) for assessing the mechanical properties of the normal patellar ligaments. Methods Eighty-eighty patellar ligaments of 44 healthy volunteers were examined. A dedicated ultrasound (US) examination was performed followed by ARFI imaging with the ACUSON S2000 ultrasound system. All measurements were performed separately by two observers within a period of 2 hours and each observer measured shear-wave speed of every tendon third twice. Longitudinal and axial images were obtained of each tendon third using US and ARFI. Results The mean thickness of patellar ligaments of the healthy volunteers is 2.99±0.33mm (range, 2.89~3.10mm). In longitudinal images, the mean speed of the proximal third is 3.24m/s, SD is 0.64; the mean speed of the middle third is 3.45m/s, SD is 0.72; the mean speed of the distal third is 3.27m/s, SD is 0.56. In transverse images, the mean speed of the proximal third is 2.85m/s, SD is 0.78; the mean speed of the middle third is 2.88m/s, SD is 0.60; the mean speed of the distal third is 2.64m/s, SD is 0.42. There was significant difference in shear-wave speed between longitudinal and transverse images（p<0.01） and measurements in transverse plane were lower than that in longitudinal plane. There was no statistically significant correlation between the shear-wave speed and sex、age or left-right side（p>0.01）.There was no significant difference among proximal third、middle third and distal third whether in longitudinal plane or in transverse plane（p>0.01）. The intra-CC values were excellent, ranging over 0.9; the inter-CC values were fair, ranging between 0.18-0.41; the values of intra-CV and inter-CV are not significant different. Conclusions ARFI has excellent repeatability and good reproducibility and it is fast and convenient to evaluate the patellar ligaments elasticity, which in the future might be used as an adjunct to conventional ultrasound to increase diagnostic accuracy.