  There are several different methods to determine the individual supernovae
(SNe) initial explosion energy, here we derive the average or typical explosion
energy of shell-type supernova remnants (SNRs) in a particular way. By solving
a group of equations pertaining to shell-type SNRs at the same stage we
obtained some physical parameters, e.g. the distance ($d$), evolved age ($t$),
etc.. Assuming series of different SN initial explosion energies ranging from
$10^{48}$ ergs to $10^{53}$ ergs, we derived series of distance and age
parameters with which compared already known ones. Thus the most likely value
of the SNe initial explosion energy is obtained when the deviation is least,
which equals to about $10^{51}$ ergs, in good agreement with the undertook
value.
