Objective: To calibrate a Quantitative Ultrasonography (QUS) system against densitometry by defining the sensitivity and specificity of the method, and to propose a series of QUS interpretation thresholds to classify the individual risk with regards to the risk of developing osteoporosis in later life. Methods: Subjects were recruited in New York City over a 1-year period. Women with amenorrhea for at least 12 months were defined as postmenopausal, and all other women as premenopausal. Bone mineral density (BMD) was measured with a dual energy X-ray absorptiometer (DXA) and QUS performed with the calcaneus of broadband ultrasound attenuation (BUA) and speed of sound (SOS) using the Lunar Achilles system. Statistical analysis was performed using SPSS software Version 10.0. Results: Two hundred twenty-eight premenopausal and menopausal women were recruited. Most of the participants were Hispanic, Caucasian and African-American in this study. All the subjects had DXA and QUS examined and T-score was got from both. The statistical results showed that the T-score of QUS has a significant relationship with that of DXA(spine: r=0.557, P＜0.0001;femur: r=0.611,P＜0.0001). Both QUS and DXA T-score has a significant and negative relationship with age (QUS: r=-0.241, P＜0.0001; Spine: r=-0.277, P＜0.0001; femur: -0.296, P＜0.0001). When T-score of heel ultrasound -1.5 was set as the interpretation threshold, the osteoporosis patients with T-score of DXA-femur scan (100%) and DXA-spine (77.10%) less than -2.5 were detected. As well, the specificities of T-score -1.5 of QUS for DXA-femur and DXA-spine were 67.5% and 72.8%, respectively. In addition, if we set -1.0 of T-score of QUS as the cutoff, 74.80% and 79.60% of the osteopenia based on DXA of spine and femur were identified. The specificities were 59.4% and 57.7%. Conclusions: QUS of the calcaneus may be an effective method for providing risk stratification for osteoporosis, and for the closely associated future risk for fragility-fracture.