Nanobubbles offer several advantages in targeted gene transfection. For example, nanobubbles are characterized by strong penetrating power and stable performance, which allow them to enter tumor tissues through the tumor vasculature. Therefore, in this study, we combined RNAi technology with nanotechnology by preparing nanobubbles carrying AR small interfering RNA. The physical properties of these bubbles were then assayed. Furthermore, the prepared nanobubbles were used for the siRNA transfection of AIPC cells together with ultrasonic irradiation treatment to induce the release of the siRNA transcripts. The in vitro transfection efficiency was systematically evaluated. Additionally, the anti-tumor efficacy of the nanobubbles was evaluated using imaging studies and a tumor growth inhibition assay in a mouse xenograft prostate cancer model. The results presented here provide experimental support for the use of nanobubbles carrying AR siRNA in combination with ultrasonic irradiation as a potential effective therapy for AIPC. To date, various gene therapy treatments utilizing viral vectors have been proposed. However, the use of viral vectors is a major concern because this vector system is associated with numerous safety concerns, including toxicity, immunogenicity, and tumorigenicity. Thus, the clinical application of viral vectors has been greatly restricted. The construction of an efficient, safe, and controllable in vivo gene delivery system has been a highly debated and challenging endeavor in the gene therapy community. The present study shows that ultrasound-mediated microbubble destruction may have the potential to become a new approach for targeted gene transfection. Other studies have also shown that ultrasound-destructible microbubbles not only enhanced gene transfection efficiency but were also potentially useful as a novel in vivo gene transfection vector for the delivery of any antisense oligonucleotide or DNA fragment. Thus, ultrasounddestructible microbubbles show great promise for clinical applications in the future. Despite this promise, some challenges remain in the application of conventional ultrasound-destructible microbubbles for gene or drug delivery to treat cancer. Most notably, the diameter of conventional ultrasound-destructible microbubbles, which ranges from 1-10 mm, likely prevents the bubbles from passing through the tumor vascular wall into the tumor tissues because the maximum pore size of the tumor vascular wall is 380–780 nm. This size discrepancy can affect the release and transfection of carried genes, ultimately decreasing the anti-tumor efficacy of these micro-scaled, ultrasound-destructible microbubbles. To address this size problem, researchers have proposed that nanobubbles may be a better alternative to conventional microbubbles as a gene or drug carrier for the treatment of tumors. Nanobubbles have a size of less than 1000 nm.