  A temperature dependence of a width of $\Delta$H = $\Delta$B region has been
studied for 5 wt.\% (Fe, Ti) particle-doped MgB$_2$ superconductor. The result
revealed that widths of the region are linear along temperature. Here we show
the meaning of the result and details of the calculation. In previous report,
we represented a theory that a width of $\Delta$H = $\Delta$B region is related
with upper critical field of the superconductor, which is that pinned fluxes at
volume defect are picked out and move in $\Delta$H = $\Delta$B region when a
distance between them is the same as that of upper critical field. Thus, we
inspected the relationship between a width of the region and upper critical
field along temperature. The theory would gain another justification if
temperature dependence of a width of the region is proportional to that of
upper critical field. We discussed several topics for $\Delta$H = $\Delta$B
region of 5 wt.\% (Fe, Ti) particle-doped MgB$_2$ superconductor, which are Fe
of (Fe, Ti) particle, Bean model, volume dependence of the region, etc..
