唐朝行人往来各地需持证明身份的旅行文书,公验即是其中的一种。过所与公验在唐朝长期并行,二者性质相似,互为补充。现有研究从文书行政的角度,对过所制度及二者的异同多有关注,但对公验制度的研究还有不足。不同于过所,公验的勘发机构更加广泛,使用范围随勘发机构的等级而变化,或行用于本地,或行用于相邻同级行政区。公验的管理比较宽松,格式相对简单,形式灵活多变,勘发官员也较为随意。正是由于这些特点,加上律令制度的破坏以及赋役制度的改革,公验逐渐取代了过所,到宋代成为唯一的旅行文书。 In the Tang Dynasty, pedestrians are required to have travel documents that prove their identities, and the examination is one of them. Excessive test and parallelism in the Tang Dynasty long-term parallel, both similar in nature, complement each other. The existing researches focus on the system and the similarities and differences between them both from the point of view of clerical administration, but there are still some deficiencies in the study of the system of appraisal. Different from the past, the probationary agencies are more extensive. The scope of application varies with the level of the institution, or it can be used locally or for adjacent siblings. The management of the test is relatively loose, the format is relatively simple, the form is flexible, and the survey officials are also more arbitrary. It is precisely because of these characteristics, combined with the destruction of the legal system and the reform of the taxation system, that the public examinations gradually replaced those of the Song Dynasty and became the only travel documents to the Song Dynasty.