This study investigated the perspectives of the K-12 principals who took part in the teacher education of computational thinking. The scales of the readiness survey questionnaire included object readiness, teacher readiness, instructional resource readiness, and leadership support. Moreover, this study also explored the TPACK of teachers for computational thinking education. The integrated questionnaire reports two validity statistics – the acceptable internal consistency (alpha reliability coefficient), and discriminant validity – for the refined 35 items. The results of the survey showed that those principals perceived the present situation which was significantly lower than the degree of importance they preferred. In other words, all the dimensions of the survey will have to be strengthened in the 2 years before conducting computational education for the 12-year compulsory education from August 2019 in Taiwan.