The present invention relates to a novel siRNA, and a high-efficiency double-stranded oligo RNA structure containing the same, and a nanoparticle containing the high-efficiency double-stranded oligo RNA structure. The double-stranded oligo RNA structure has a structure in which a hydrophilic material and a hydrophobic material are conjugated to both ends of a double-stranded oligo RNA (siRNA) via a simple covalent bond or linker-mediated covalent bond in order to be efficiently delivered into cells, and may be converted into a nanoparticle form in an aqueous solution by hydrophobic interactions of double-stranded oligo RNA structures. It is preferable that the siRNA contained in the double-stranded oligo RNA structure is an siRNA specific for fibrosis or respiratory disease-related gene, particularly, amphiregulin or stratifin.In addition, the present invention relates to a pharmaceutical composition for preventing or treating fibrosis or respiratory diseases, containing an siRNA, a high-efficiency double-stranded oligo RNA structure containing the siRNA, or a nanoparticle containing the high-efficiency double-stranded oligo RNA structure, as an active ingredient.In addition, the present invention relates to a method of preventing or treating fibrosis or respiratory diseases, including administering the pharmaceutical composition for preventing or treating fibrosis or respiratory diseases to a subject in need thereof.