Topological indices which are graph invariants derived from molecular graphs of molecules are used in QSPR researches for modeling physicochemical properties of molecules. Topological indices are important tools for determining the underlying topology of a molecule in view of theoretical chemistry. Most of the topological indices are defined by using classical degree concept of graph theory. In this study, we firstly define the new five versions of harmonic indices. And also we compute the fifth harmonic index of H-Naphtalenic nanotube and TUC4[m, n] nanotube.