The fabrication of nonoporous alumina membrane is a sensitive process. Making small diameter anodic aluminum oxide (AAO) tubular membrane is crucial for applications where large surface area is needed. Hemodialysis, protein separation and molecular sieving are some of target areas where small diameter AAO tubular membrane can be used. In this paper a simple method to fabricate AAO nanoporous tubular and rectangular membrane is introduced. This method is based on cracking behavior of alumina when grown at two faces of aluminum (Al) perpendicular to each other. These cracks are utilized to fabricate 2D and 3D structures such as rectangular and tubular membranes. This method does not need Al tube to fabricate tubular membrane instead a hole is drilled in Al and follow by anodization process. In the anodization process cracks appear at every edge. During Al etching, tubular membrane and plane membrane separates from each other. This method does not need to insulate Al from any side in the electrolyte solution or cutting any surface mechanically. Using this method AAO tubular membranes from 825μm to 1.8 mm diameter were fabricated successfully. The nanoporous membranes were fabricated from 35 nm up to 81 nm pore diameter and 1.43μm to 114μm thickness. The fabricated AAO tubular membranes were uniform and the nanopores were in hexagonal order.