In this paper, we prove the existence of eigenvalues for the problem ϕ p u (t) + λh(t)ϕ p u(t) = 0, a.e. in (0, 1),where ϕ p (s) = |s| p−2 s, p > 1, λ is a real parameter and the indefinite weight h is a nonnegative measurable function on (0, 1) which may be singular at 0 and/or 1, and h ≡ 0 on any compact subinterval in (0, 1). We derive similar properties of eigenvalues as known in linear case (p = 2) or continuous case (h ∈ C[0, 1]) if h satisfies 1 0 t p−1 (1 − t) p−1 h(t) dt < ∞ when 1 < p 2 and 1/2 0 ϕ −1 p ( 1/2 s h(τ ) dτ ) ds + 1 1/2 ϕ −1 p ( s 1/2 h(τ ) dτ ) ds < ∞ when p 2, respectively. For the result, we establish the C 1 -regularity of all solutions at the boundary for the above problem as well as the following problem:where f ∈ C(R, R), sf (s) > 0 for s = 0, f is odd and f (s)/ϕ p (s) is bounded above as s → 0.