As miniaturization of product becomes a trend, meso-machining technique for relevant components becomes necessary. Micro- milling with small size cutter is one of the key techniques for meso-manufacturing. When size of tool becomes small, feasible range of process parameter becomes limited. Without properly selected parameter, it could result in cost increase and quality unacceptable. Optimization of micro-milling to maximize removal rate and tool life is an important issue. This study aims at developing an optimization module using genetic algorithm for micro-milling. A milling experiment for constructing a prediction model of tool life was conducted. A computer program based on Pareto genetic algorithm was coded to search for optimized solution. A set of non-dominated solution satisfying dual objectives was obtained as the result. The solution can be used for determining milling parameter based on process interest.