  New fissile isotopes antineutrino spectra ($^{235}$U, $^{238}$U, $^{239}$Pu
and $^{241}$Pu) calculation is presented. On base of summation method the toy
model was developed. It was shown that total antineutrino number is conserved
in framework of given database on individual fragments yields. The analysis of
antineutrino spectrum shape says that any presented antineutrino spectrum
should satisfy to the total antineutrino number conservation.
