In this chapter, we introduce our recent work on the development of new antisense strategies in RNA synthetic technology and RNA drug discovery. In the first part of the chapter, we briefly introduce selected chemical modifications of antisense oligomers and recent developments in antisense RNA. In the second part, we describe our research on RNA, including synthetic approaches to stereodefined backbone-modified oligoribonucleotides with chiral linkages, and the development of a method for the synthesis of RNA based on the use of 2-cyanoethoxymethyl (CEM) as the 2 0 -hydroxyl protecting group. The CEM method has been applied to the synthesis of single and double short hairpin RNA, pre-microRNA, and designed mRNA molecules up to 170 nucleotides in length, which were physicochemically identified and shown to be biologically active. We hope that the work presented here will contribute to the pushing forward of the frontiers of knowledge and understanding in RNA biology and RNA drug discovery.