We evaluated the relationship between the radiological indices that assessed the proximal femoral morphology and the degree of osteoporosis in 45 Chinese cadaveric femora. Canal-calcar ratio, canal flare index, morphological cortical index, and canal bone ratio were determined in the plain anteroposterior radiographs. Canal bone ratio is the ratio between the endosteal and outer diameters of the proximal femur at 10 cm below the lesser trochanter. Bone mineral density of the proximal femora was measured with dual-energy x-ray absorptiometry, and T score that depicted the degree of osteoporosis was determined. Canal bone ratio showed a strong correlation with the T score (r = -0.71, P < .001) and the best overall performance in diagnosing osteoporosis with receiver operating characteristic curve analysis. The proximal femur was likely to be osteoporotic if the canal bone ratio was 0.49 or higher.