We consider the solvable intervals of three positive parameters λ i (i = 1, 2, 3) in which the second-order impulsive boundary value problemx (1) = 0, y(0) = y(1) = 0 admits at least two positive solutions. The main interest is that the weight functions a(t), b(t), and g(t) change sign on [0, 1], λ i (i = 1, 2, 3) ≡ 1, and I k = 0 (k = 1, 2, . . . , n). We will obtain several interesting results: there exist positive constants λ * , λ * , λ * i (i = 1, 3), λ * * i (i = 1, 2, 3) and α with α = 1 such that:and λ 2 ∈ [λ * , λ * ], the above boundary value problem admits at least two positive solutions; (ii) if 0 < α < 1, then for λ i ∈ (0, λ * * i ] (i = 1, 2, 3), the above boundary value problem admits at least two positive solutions.