An introduction of cellular automata for its developing history, theory, and applicability fields were presented in the paper. A preliminary simulation of Chushui stream debris flow hazard in Nantou county, Taiwan, by cellular automata methodology was presented for revealing the capacity of cellular automata on simulation of complex natural phenomena. The framework to set up a cellular automata simulation was suggested for a beginner to study natural phenomena. The combination of cellular automata with available fields, for example, geography information system, for further applications was suggested.