  Unitarity cut method has been proved to be very useful in the computation of
one-loop integrals. In this paper, we generalize the method to the situation
where the powers of propagators in the denominator are larger than one in
general. We show how to use the trick of differentiation over masses to
translate the problem to the integrals where all powers are just one. Then by
using the unitarity cut method, we can find the wanted reduction coefficients
of all basis except the tadpole. Using this method, we calculate the reduction
of scalar bubble, scalar triangle, scalar box and scalar pentagon with general
power of propagators.
