Does the subject want to ask, "Do you have to be recommended by a doctoral tutor to apply for a postdoctoral position in China?" ? I have to. The recommendation letter of the doctoral supervisor is the necessary reference material, and you must have the recommendation letter of the doctoral supervisor after applying for the doctoral degree in China. Postdoctoral (postdoctoral researcher/associate researcher/researcher, abbreviated as Postdoc) refers to those who engage in academic research or research in institutions of higher learning after obtaining a doctorate, usually working in postdoctoral mobile stations or postdoctoral research centers.