In this paper, we investigate the existence and nonexistence of the solutions for two kinds of quasilinear elliptic equation or system.In chapter1, we consider the equation△mu=p(x)uα+q(x)uβ,0<α≤β.(0.0.3) where p, q are nonnegative continuous functions and0<α≤β. We con-sider the existence and nonexistence results of explosive solutions for β> m-1(superlinear/mixed case), and the existence results both for explosive solution and bounded solution for β≤m-1(sublinear case).In chapter2, the existence of entire solutions for the following quasilinear elliptic systems are considered, wheref, g are continuous and non-decreasing on [0,∞), satisfying the Keller-Osserman condition. We establish conditions on p and q which are necessary for the positive solutions to be bounded or unbounded. |