Abstract: Objectives To study the rule of ultrasonic bone mineral density of calcaneus with age, height and body weight, and establish the normal reference value of stiffness index (SI) of females in Chinese southern region and provide scientific foundation for osteoporotic diagnosis and prevention. Methods SI for calcaneus in 2498 healthy people 10-87 years old were measured with Achilles Express ultrasound apparatus made in USA. They were divided into groups according to sex and age. One group for 10 years each and the records beyond 69 years were classified into one group, total 7 groups. Results The SI exhibited a characteristic mild rise-then-fall pattern with increasing age. And the peak value of SI presented in 20～29 age group. Pearson correlation analysis showed negative correlation between SI and age and positive correlation between SI and height and weight. The prevalence of osteoporosis increased gradually with age. Conclusion There were significant correlations in SI with age, height and weight; the values of SI will provide an important data reference to establish the normal values and diagnostic standard of osteoporosis.