Objective To study the geometric features of proximal femur for the Chinese AVN population so as to provide anatomical references for hip prosthesis selection and design. Methods From January 2004 to August 2008, we collected 186 patients which 281 hips undertaken total hip arthroplasty for AVN. All the standard anteroposterior(AP) and mediolateral (ML)X-ray films were obtained and measured to observe the proximal canal geometry by curve fitting technique. All cases with completed data were analysed respectively according to gender and age. Results 59 cases couldn’t obtain completed data and were excluded for unclear cortical margin and severe collapsed femoral head. The completed data from 127 cases were studied and successfully established medial, lateral, anterior and posterior curves to observe the proximal canal geometry. According to age, the medial part of the distal femur had statistical difference, while according to gender, there was no statistical difference. However, compared with data of normal Chinese population, there was difference at the proximal part of lesser trochanter. Conclusion We gained a large series data of AVN proximal femur and fitted 4 curves for describing the canal of AVN population. The results not only provide useful information of AVN, but also indicate that AVN, as a kind of disease, has the potential of an independent factor affecting the geometric features of proximal femur.