Conference participants may need a Chinese visa to enter China. Specifically, those who are not Chinese citizens, need a Chinese visa. Participants can apply for a visa at the Chinese embassy or consulate in the region in which they live. For most attendees, it is easier to apply for a Tourist ("L") visa; an invitation letter is not required for obtaining a Tourist visa. If some participants need another type of visa that does require an invitation letter, the ICML 2014 organization committee will be glad to help. If you need an invitation letter, please send e-mail to local chairs (Changshui Zhang,Jun Zhu,Tie-Yan Liu), together with your registration, and in the case of being an author, your accepted paper ID.
To avoid uncertainty, participants will be advised to apply for a visa as early as possible. It is recommended that they apply for a Chinese visa at least 1 month in advance.
For more information regarding the requirements and procedure for obtaining a visa to China, please see https://www.visaforchina.org/, if your country is not listed on that website, please search for embassy or consulate in your region.
For example, Embassy of China in USA is at http://www.china-embassy.org/eng/visas/.