Arts design has been proven to enable designers to have a meaningful learning of STEAM, but research on a checklist for assessing Arts design based on evaluating entries in a STEAM contest is still rare. Therefore, this study developed a checklist for assessing Arts design for evaluating miniature robots in a STEAM contest. Using an example of STEAM contest, named PowerTech, which has been held 22 years in Taiwan, we developed five dimensions of the checklist are: aesthetics, material usage, bionic, performance, and additional devices. There are two sub-indices in each aspect to be considered as the identification of form characteristics. Eight international experts were invited to review the content validity of the Arts design scale, and 30 completed checklists were used to test the reliability and validity though Kendall's coefficient of concordance. The results showed that the Arts design scale had high reliability and good validity, and so rubric index could be used to measure and assess Arts design with miniature robots in that integrated STEAM contest. Based on this, it is suggested that educational authorities can refer this study and for encourage students to create Arts in any integrated STEAM contests.