Available field data has shown interference between parallel, hydraulically-fractured horizontal wells in gas reservoirs, which indicates potential deviations with the prevailing single-well simulations. Three-dimensional, multi-phase, multi-well, multi-fracture simulation of gas production from unconventional reservoirs are performed to investigate the interference mechanism as functions of fracture characteristics. Realistic well configuration, reservoir condition and production data are used in the modeling scenarios. Results will provide insights on the significance of multi-well interference in practical productions.