The phenomena of liquid drop impacting onto solid surfaces exist widely in nature and industrial production. In-depth study of liquid drop impacting is thus of great importance to environmental engineering, micro-nano engineering, bio-and chemical engineering. This paper presents a numerical simulation of a single liquid drop impacting onto solid surfaces with smoothed particle hydrodynamics (SPH). SPH is a Lagrangian, mesh-free particle method, and it is attractive in dealing with free surfaces, moving interfaces and deformable boundaries. In order to improve computational accuracy, the modified schemes of kernel gradient for SPH were used. Surface tension effects were modeled using the interaction force between particles, the modified SPH method was used to investigate liquid drop impacting onto solid surfaces. It is demonstrated that the SPH method can effectively simulates the problem of liquid drop impacting onto solid surfaces. It can well describe the dynamics of splashing and spreading with accurate and stable results. The obtained numerical results agree with experimental observations.