Abstract: [Abstract] Objective To analyze the related factors of the prognosis after replantation of the avulsed young permanent teeth. Methods 50 avulsed young permanent teeth of 46 patients from the clinic which were replanted based on the guideline of the teeth injuries were observed, from 2008 to 2011, about the storage pattern, replantation time, the development level of the root, time of pulp remove and the prognosis. The observing period lasted from 6 months to 2 years. Results 74% of 50 teeth were in dry storage and 70% came to clinic over 60 min after injury. The less root development was (Nolla 7), the longer pulp necrosis needed to be observed. The closer root development was to completion (Nolla 9), the faster dental pulp necrosis appeared. Conclusion The prognosis is better in the condition of shorter root development and shorter time of dry storage in the young permanent teeth avulsion.