  We present a formalism to obtain equilibrium configurations of uniformly
rotating fluid in the second post-Newtonian approximation of general
relativity. In our formalism, we need to solve 29 Poisson equations, but their
source terms decrease rapidly enough at the external region of the matter(i.e.,
at worst $O(r^{-4})$). Hence these Poisson equations can be solved accurately
as the boundary value problem using standard numerical methods.This formalism
will be useful to obtain nonaxisymmetric uniformly rotating equilibrium
configurations such as synchronized binary neutron stars just before merging
and the Jacobi ellipsoid.
