  In Ising model on the simple cubic lattice, we describe the inverse
temperature \beta in terms of the bare-mass M and study its critical behavior
by the use of delta expansion from high temperature or large M side. In the
vicinity of critical temperature \beta_{c}, the expansion of \beta in M has
\beta_{c} as the first term and M^{-1/2\nu} as the leading correction. The
estimation of \beta_{c} in 1/M expansion is confronted with the leading and
higher order corrections, even delta expansion is applied and the critical
region emerges. To improve the estimation status of \beta_{c}, we try to
suppress the corrections by adding derivatives of \beta(M) with free adjustable
parameters. By optimizing the parameters with the help of the principle of
minimum sensitivity which are maximally imposed in accord with the number of
parameters, estimation of \beta_{c} is carried out and the result is found to
be in good agreement with the present world average. In the same time, the
critical exponent {\nu} is also estimated.
