We study the bifurcation diagrams of positive solutions of the multiparameter p-Laplacian problemwhere p > 1, ϕ p (y) = |y| p−2 y, (ϕ p (u )) is the one-dimensional p-Laplacian, f λ,μ (u) = g(u, λ) + h(u, μ), and λ > λ 0 and μ > μ 0 are two bifurcation parameters, λ 0 and μ 0 are two given real numbers. Assuming that functions g and h satisfy hypotheses (H1)-(H3) and (H4a) (resp. (H1)-(H3) and (H4b)), for fixed μ > μ 0 (resp. λ > λ 0 ), we give a classification of totally eight qualitatively different bifurcation diagrams. We prove that, on the (λ, u ∞ )-plane (resp. (μ, u ∞ )-plane), each bifurcation diagram consists of exactly one curve which is either a monotone curve or has exactly one turning point where the curve turns to the right. Hence the problem has at most two positive solutions for each λ > λ 0 (resp. μ > μ 0 ). More precisely, we prove the exact multiplicity of positive solutions. In addition, for all p > 1, we give interesting examples which show complete evolution of bifurcation diagrams as μ (resp. λ) varies.