This research, deeply examines to what degree, Iranian EFL teachers improved their design knowledge, for knowledge, for online education. For this reason, a survey questionnaire which was based on Kim's (2019) Teacher Design Taxonomy, was conducted and sent to 282 EFL teachers (who have started their teaching just several months), by E-mail to investigate what sort of Data, Knowledge, and Design practice helped them to teach online as well as developing their teaching practices. The results of the study showed that Iranian EFL teachers have more common and simple design tools and practices such as documentation of available designs, expansion of documenting course materials, visualizations, and appropriating design principles through learning. Interestingly, the teachers stated that they have high tendency for expansive learning and gaining knowledge for design tools through online teaching. Moreover, the results proved that they had very insufficient information about manipulating and analyzing students' learning data, developing new design principles in new design, epistemic agency for idea-centered discourse, and formative assessment for knowledge-creating (Kim, 2019, p. 4). Consequently, this research highlighted that Iranian EFL teachers are at the preliminary stage of distance education while they are going through the difficult and complicated, stages of online teaching education.