Of the remaining unknown parameters of neutrinos, the leptonic CP phases are of profound importance by providing a window for us to understand why matter exists in the Universe. I will talk about some phenomenological studies on the leptonic CP phases, both Dirac and Majorana types. The Dirac part introduces how residual symmetries can predict the CP phase as a function of the three neutrino mixing angles and improved measurement with muon decay at rest (muDAR) while the Majorana part will show the possibility of constraining the two Majorana CP phases simultaneously. We will enter a new era of precision measurement on leptonic CP phases which can tell us the deep secrets of nature.
1) Residual symmetry: 1104.0602, 1108.0964, 1308.6522
2) TNT2K experiment with muDAR: 1506.05023, 1605.01670, 1607.08513
3) Majorana CP: 1608.01618