The fluid continuity equations of the hybrid model are developed for the coupled stress and fluid flow in two-dimension (2-D) saturated fractured rock. The fluid continuity equation for blocks is based on Oda’s two-spring parallel-plates model for a fracture, and this equation is different from that of soil-like porous media in the capacity term. The fluid continuity equation for domains surrounded by blocks is based on its real-in-time geometrical configuration, and accounts for the fluid interactions between blocks and domains. Thus, it can cover all spectra of coupled stress and fluid flow under venous conditions. It is illustrated that the developed equation for domains embraces the conventional one based on infinitesimal element. The fluid continuity equations of the hybrid model are developed for the coupled stress and fluid flow in two-dimension (2-D) saturated fractured rock. The fluid continuity equation for blocks is based on Oda’s two-spring parallel-plates model for a fracture , and this equation is different from that of soil-like porous media in the capacity term. The fluid continuity equation for domains surrounded by blocks is based on its real-in-time geometrical configuration, and accounts for the fluid interactions between blocks and domains . Thus, it can cover all spectra of coupled stress and fluid flow under venous conditions. It is illustrated that the developed equation for domains embraces the conventional one based on infinitesimal element.