Abstract: 4-Azasteroids as important 5α-reductase inhibitors play a critical role in therapy of several human endocrine diseases, such as benign prostatic hyperplasia, male pattern baldness, female hirsutism, etc. Starting from 4-androstenedione, three novel 3-oxo-4-aza-5-androstene-17-oxime derivatives 7, 8 and 9 were synthesized through oxidation ring cleavage, amination ring closure, oximation,and substitution. The structures of these novel compounds were identified with MS,1H NMR and 13C NMR.