Nanostructured thin films have been widely applied for anti-reflective components and self-cleaning surfaces. The roller mold for production of nanostructured films mostly relies on expensive processes, such as e-beam or focused ion beam. This study develops an effective, fast, and low-cost method to fabricate seamless anodic aluminum oxide (AAO) roller mold, which then be employed to fabricate nanostructures on the surface of polycarbonate (PC) continuously by roller hot embossing. The alumina oxide membranes with nanopores of 80 nm, 160 nm and 430 nm in pitches were fabricated via two-step anodization, and the employed anodization voltage are 40 V, 80 V and 180 V, respectively. The SEM photos show that the fabricated nanopores are similar as observed from all degrees of the surface. However, there are microholes on the surface due to the purity of the aluminum is only 99%. The aluminum with higher purity, including a 99.999% purity aluminum foil and a roller which were sputter coated with a 99.99% purity aluminum layer, were anodized in this research. The result show that using higher purity aluminum could obtain anodic aluminum oxide with better arrangement and without microholes on surface because less impurities exist. The seamless AAO roller mold fabricated in this research has been utilized to continuous hot rolling process. Comparing to plate form hot embossing, hot rolling has the advantage of high speed, continuous, large area, and suit for mass production. Since the mold itself is seamless, in this work, the nanostructures on the AAO roller mold can be replicated onto the PC substrate with no restriction of length and seam defect, providing the nanostructured films various ways of application.