Abstract: To investigate the effect of irregular shape and distribution of porous media on groundwater flow and solute transport, a double-layer herringbone structure was artificially constructed and numerical simulations of groundwater flow and transport were performed. Such a structure simulates the existing inclined cross-bedding geological features and forms macroscopic anisotropic hydraulic conductivity field. The results show that the macroscopic anisotropic structure creates helical flow, leading to the stretching and folding of the streamlines and the irregular deformation of the solute plume, and thus, solute dilution is enhanced significantly. The vertical relative position between the macroscopic anisotropic structure and the solute plume has a remarkable effect on solute transport.