This case study aims to explore the currently utilized design, identify barriers, and factor contributed to the preparation training (PPT) improvement during the COVID-19 (Corona Virus) pandemic. A participant observation, an online questionnaire and an in-depth interview used in the study, in which a total of 304 prospective school principals participated in the first PPT cohort in online modality. The analysis results show that the PPT improved knowledge, skill, and motivation. However, there are several barriers in the new PPT concerning 1). Lack of ICT literacy in operating LMS Moodle and making video for online exhibition; 2). Poor internet connection because of bad weather, electricity problem, and living in remote area; 3). Slow learning in ICT utilization, because most of participants were in between 48-55 years old, and 4). Duration of synchronous meeting is too long. The proposed improvement of this study are time management, human capacity improvement, regrouping participants based on learning need, reducing synchronous meeting, modifying assignments, providing internet package and hotspot area. The results of this study may become a baseline for improving quality of the PPT in Indonesia. For further research, it is important to highlight that the data were obtained in the Indonesian training context and in online modality. Consequently, further study is encouraged in different contexts and different modalities.