In recent years, rapid development of aerospace and aeronautic industries demands for light-weight, high strength, and fatigue resistant aluminum alloys. Predictions of cast defects and technologies of controlling those defects become more and more important. Hydrogen porosity is one of the major initiators for the fatigue failures of aluminum alloys, which forms during solidification. In the foreign companies, mathematical models such as cellular automaton (CA) model have been widely used to optimize the advanced casting practices such as single crystal turbine blades, turbine disc, and exterior frames for aircraft engines. This paper summarizes the most recent progresses of defect prediction models for solidification process, and propose the future directions for modeling of casting defects.