We study the Cauchy problem for the quasilinear wave equationx with a ≥ 0 and show a result for the local in time existence under new conditions. In the previous results, it is assumed that u(0, x) ≥ c 0 > 0 for some constant c 0 to prove the existence and the uniqueness. This assumption ensures that the equation does not degenerate. In this paper, we allow the equation to degenerate at spacial infinity. Namely we consider the local well-posedness under the assumption that u(0, x) > 0 and u(0, x) → 0 as |x| → ∞. Furthermore, to prove the local wellposedness, we find that the so-called Levi condition appears. Our proof is based on the method of characteristic and the contraction mapping principle via weighted L ∞ estimates.