Objective: A resilient health system plays a crucial role in pandemic preparedness and response. Although the World Health Organization (WHO) has required all states parties to strengthen core capacities to respond to public health emergencies under the International Health Regulations (2005), the actions of most countries to combating coronavirus disease 2019 (COVID-19) has showed that they are not well-prepared. This cross-sectional study aimed to examine the health system resilience of selected countries and analyze their strategies and measures in response to the COVID-19 pandemic.Methods: This study selected five countries including the Iran, Japan, Republic of Korea (South Korea), the U.K., and the U.S., based on the severity of the national epidemic, the geographical location, and the development level. Cumulative number of death cases derived from WHO COVID-19 dashboard was used to measure the severity of the impact of the pandemic in each country; WHO State Parties Self-Assessment Annual Reporting (SPAR) Scores and Global Health Security (GHS) Index were applied to measure the national health system resilience; and research articles and press materials were summarized to identify the strategies and measures adopted by countries during response to COVID-19. This study applied the resilient health systems framework to analyze health system resilience in the selected countries from five dimensions, including awareness, diversity, self-regulation, integration and adaptation. Results: The SPAR Scores and GHS Index of the four developed countries, Japan, South Korea, the U.K. and the U.S. were above the global and regional averages; the SPAR Scores of Iran were above the global average while the GHI Index lain below the global average. In terms of response strategies, Japan, the U.K. and the U.S. invested more health resources in the treatment of severe patients, while South Korea and Iran had adopted a strategy of extensive testing and identification of suspected patients. In terms of specific measures, all the five countries adopted measures such as restrictions on entry and international travel, closure of schools and industries, lockdown and quarantine. Nevertheless, the effectiveness of implementing these measures varied across countries, based on the response strategies. Conclusion: Although SPAR Scores and GHS Index have evaluated the national core capacities for preparedness and response, the actions to cope with the COVID-19 pandemic has revealed the fact that most countries still do not build resilient health systems in response to public health emergencies. Health system strengthening and health security efforts should be pursued in tandem, as part of the same mutually reinforcing approach to developing resilient health systems.