Perceptions towards the COVID-19 Pandemic during Different Lockdown Levels among International Students in Taiwan

International students face many impediments under the COVID-19 pandemic. The objectives of this study are to assess the association between the perceptions of international students and the lockdown policy for COVID-19. In 2021, three different levels of lockdown policy were enforced, including level I from January to April, level III from May to July, and level II from August to December. We conducted three surveys for international graduate students using a validated questionnaire during the different lockdown levels. We collected 185, 119, and 83 valid questionnaires in level I, II, and III, respectively. There were linear trends in the correlations of lockdown policy with the knowledge (p = 0.052), attitudes (p = 0.002), and practices (p < 0.001) of COVID-19. In brief, the stricter the lockdown policy, the better the students adhered to sufficient knowledge, positive attitudes, and healthy practices. Furthermore, there were significant linear correlations of lockdown policy with the transportation, school study, leisure, family life, and diet behavior. In conclusion, lockdown policy had important impacts on the knowledge, attitudes, practices, and daily lives of international students. The findings indicated that the lockdown system and its corresponding measures appear to affect perceptions in a positive way.