A strong-coupling-limit theory of the normal-state hole dynamics in co
pper oxide superconductors is developed. The theory is based on the t-
t'-J model and the diagrammatic technique for Hubbard operators. We ha
ve analyzed the evolution of the hole dynamics with doping and have fo
und that the Fermi surface of the itinerant quasiparticles changes abr
uptly at low doping from small with volume proportional to the concent
ration of doped holes delta to large with a volume proportional to 1 delta. The ground state with the small Fermi surface is unstable agai
nst long-range antiferromagnetic ordering. The state with a large Ferm
i surface is characterized by a close disposition of the Fermi level a
nd of the saddle-point singularity within an extended range of doping,
delta = 0.1-0.4. The results account well for the data of angle-resol
ved photoemission experiments, Some effects of an electronic topologic
al phase transition occurring at delta = delta(c) (the doping which co
rresponds to the intersection of the Fermi level and the saddle-point
singularity) on the physical properties are discussed.