Abstract: Over the past decades, the relativistic density functional theory has been greatly developed and successfully applied to a variety of nuclear phenomena. We will briefly introduce the concept of this theory in nuclear physics, and review a few important applications such as studies on nuclear ground state properties and chiral rotations，as well as nuclear dynamics. Moreover, the ideas to build a microscopic and universal density functional based on the fully self-consistent relativistic Brueckner—Hartree—Fock calculations are discussed.