In current society, quality of production is more important than before. The serial production system is still the mainstream in the manufacturing industries, before the product delivery to customer, the product need to go through many processes, then it could produce defective products. In this study, we use the Dynamic Programming and Ant Colony Optimization to find the optimizing inspection strategies in serial production system. Demonstrated by an example the decision rule applied in this study and the findings and conclusions, as a follow-up studies and hopes to provide to the industry's reference.