2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/213714We re-express the Kerr metric in standard Bondi-Saches' coordinate near null infinity ${\cal I}^+$. Using the uniqueness result of characteristic initial value problem, we prove the Kerr metric is the only asymptotic flat, stationary, axial symmetric, Type-D solution of vacuum Einstein equation. The Taylor series of Kerr space-time is expressed in terms of B-S coordinates and the N-P constants have been calculated.15pagesGeneral Relativity and Quantum Cosmologytext