The ground-state bands of 248,250,252 Cf have been established up to the 10 + , 12 + , and 10 + states, respectively, by in-beam γ -ray spectroscopy using neutron-transfer reactions with a 153-MeV 18 O beam and a highly radioactive Cf target. The deexcitation γ rays in 248,250,252 Cf were identified by taking coincidences with outgoing particles of [16][17][18][19] O measured with Si E-E detectors, and by selecting their kinetic energies. Moments of inertia of 248,250,252 Cf were discussed in terms of the N = 152 deformed shell gap.