Renormalization group invariants in neutrino sector

We show renormalization group invariants in neutrino sector. These are found from a simple analytical discussion of Majorana mass matrix for light neutrinos. It is shown that the invariants are obtained by taking ratios among elements of the Majorana neutrino mass matrix. The invariance is independent of neutrino mass ordering and a parameterization of mixing matrix for the lepton sector. Parameters in the runnings under renormalization group equations in the neutrino sector are also analyzed.