We study the boundary value problem of the quasi-linear elliptic equation div |∇u| m−2 ∇u + f (x, u, ∇u) = 0 in Ω,where Ω ⊂ R n (n 2) is a connected smooth domain, and the exponent m ∈ (1, n) is a positive number. Under appropriate conditions on the function f , a variety of results on existence and non-existence of positive solutions have been established. This paper is a continuation of an earlier work Zou (2008) [18] of the author and, in particular, extends earlier results of Brezis and Nirenberg (1983) [3] for the semi-linear case of m = 2, and of Pucci and Serrin (1986) [12] for the quasi-linear case of m = 2.