Abstract:The paper presents a study of the existence of positive solutions for a class of nonlinear second order impulsive differential systems with two parameters and the nonexistence of positive solutions,where the nonlinear terms have different properties and their coefficients a1(t),a2(t) are LPintegrable.By applying the theory of the fixed point index and constructing a special cone,the existence theorem of positive solutions is proved when parameters λ and μ have different conditions,and the nonexistence theorem of positive solutions is proved while λ is sufficiently small.