ABSTRACT: In this paper, we formulate a fluid-solid coupling scheme based on DDA for a single phase compressible fluid. For the fluid motion, we adopt a pipe network model. We start with setting up the fluid channel geometry and layout. We then derive the material balance equations mainly focusing on the application of hydraulic fracturing. Fluid pressures are treated as line loadings and added into the simultaneous equations for rock blocks. Following Shi’s original work, graph theory is used to store the non-zero elements in solving the equations of fluid pressure. Finally we discuss an iterative coupling strategy.