Abstract: In order to clarify the relationship between the elasticity modulus (Youngs modulus) and the mineral content of the shaft of human femur, the present authors chose 18 normal male dry femurs around 40 years of age cut into 202 slices as testing samples around 5--20 mm. The mineral content of every sample was measured by the 7 ray mineral content of bone analysis apparatus and the longitudinal stress by the WE-10(A) Universal Test Machine in the elasticity limitation of femur; the change of thickness of every sample was measured by the micrometer. Then the elasticity modulus of each sample was computed. The results are as follows: the area density of mineral content of femur shaft varies from 1.3g1 cm^2 to 1.9g/ cm^2. The elasticity moduli vary directly with the mineral content under 1.8g1 cm^2 while inversely with it when above 1.9g/ cm^2.
Finally their relationship as well as significances has been discussed.

Key words: Shaft of human femur; Elasticity modulus (youngs modulus); Mineral content of bone; Area density of mineral content of bone