In this paper a detailed study is performed to the ionic abundance in hot plasmas at definite temperatures and densities of matter by employing both the theory f fluctuation of entropy and Boltzmann relation on the relativistic Hartree-Fock-Slater self-consistent field average atomic model.A convolution method for fast calculation of ionic abundance is presented.The degree of ionization and ionic abundance following the changes of temperature and density of matter is discussed by taking gold as an example.