  For a general solution of the third Painlev\'e equation of complete type we
show the Boutroux ansatz near the point at infinity. It admits an asymptotic
representation in terms of the Jacobi sn-function in cheese-like strips along
generic directions. The expression is derived by using isomonodromy deformation
of a linear system governed by the third Painlev\'e equation of this type. In
our calculation of the WKB analysis, the treated Stokes curve ranges on both
upper and lower sheets of the two sheeted Riemann surface.
