In this study, we developed a dry trap for diamondback moths (DBM) (Plutella xylostella) that is baited with sex pheromones. In developing this trap, we evaluated and compared the trapping competencies of different types of up-traps that featured different layers, diameters, and structures. We also evaluated the economic value, convenience, and effectiveness of various dry-traps. All evaluations were conducted in cauliflower fields at Puyan, Changhua from 2005 to 2013. The structure of evaluated traps included 2-up traps with a diameter of 8.8 cm, an entrance diameter of 1.0 cm, and ventilators on the lower part of the bottle wall.