Xu Youjing is a Chinese author about whom little public information is available; neither the years of birth and death, nor educational background, nor specific personal experiences have been clearly recorded. The library currently holds one work by this author, Yesterday's World, which is classified under general biography. Judging from this category and the title, the work is likely a memoir or biographical narrative, carrying a sense of looking back on the past and tracing personal and historical memory. Such writing usually emphasizes authenticity of narration and the accumulation of detail, with the author often adopting the perspective of a witness or organizer to connect scattered fragments of life into a readable text. Since information about Xu Youjing's body of work and life remains insufficient, it is too early to assess the overall style and influence of this author; nevertheless, Yesterday's World can be regarded as the main basis for this author's presence among Chinese readers and offers limited clues for further understanding.