National security is the bedrock underpinning the stability of the country. Since the 18th National Congress of the CPC, the CPC Central Committee with Comrade Xi Jinping at its core has developed a holistic approach to national security by combining Marxist national security theories with the security practice of contemporary China and Chinese traditional strategic culture. The new approach follows the trend of the times and takes into account the strategic requisites of upholding and developing socialism with Chinese characteristics in the new era. The 19th National Congress of the CPC confirmed safeguarding national security as a basic policy underpinning the endeavors to uphold and develop socialism with Chinese characteristics in the new era and incorporated into the Party Constitution. This book makes detailed and enlightening analyses of both frontier ideas and cases of national security, covering such hotspot fields as economic security, cyber security, AI, data security, cultural security, and bio-security.