Objective　To explore digital measurement of the lesser trochanter anatomy on three-dimensional reconstruction of CT images of the femur so that reasonable parameters can be provided for design of Proximal femoral fixation system.    Method    CT scanning of Intact adult femur was conducted (left 40, right 40), the three-dimensional reconstruction of the femur was performed using Mimics10.01 software on the basis of the CT data. The bony landmarks determining relevant anatomy were made on the three-dimensional images of the normal femur. Measurement included the anatomic indexes of the lesser trochanter.    Results　Length of the vertical axis of the lesser trochanter was (27.01±1.72)mm and its the transverse diameter was(17.82±1.22)mm. The angle of retroversion and the up-dip angle was （22.42±9.08）°and （17.02±2.02）°, respectively. The minimum length of the screw which was used to fix the lesser trochanter of femur was (49.25±3.20) mm, The Height and the volume of the lesser trochanter was (8.59±1.44) mm and (755.91±150.14) mm3, respectively. There was no statistically significant difference of the abovementioned parameters in two sides.　Conclusion　It is feasible to accurately identify the anatomy landmarks on the three-dimensional reconstruction of the femur. Digital measurement of the lesser trochanter anatomy can provide reasonable parameters for design of the proximal femoral fixation system.