The 1st International Conference on Ultrafast Science (USC 2021) will be held in Xi’an, the starting point of Silk Road as well as the famous ancient capital city of China, from November 18th to 21st, 2021. This conference is a frontier forum on science and technology in the field of Ultrafast Science. The conference covers eight academic topics. A number of famous international and domestic experts and scholars will be invited to give presentations. The contributed papers will be published in the Proceedings of SPIE (EI indexed) or Ultrafast Science, Acta Photonics Sinica (EI indexed) after peer review process.