Abstract: In order to provide basis for preventing and controlling apple replant disease，the effects of different concentrations of sulfur（0，0.1，0.3，0.5 g ? kg-1）on soil microbial environment and replanting of Malus hupehensis Rehd. seedlings in aged apple orchard soil were studied by using pot test. The results of greenhouse and open-field pot showed that sulfur had a good effect on improving the replanted soil environment and promoting the growth of M. hupehensis Rehd. seedlings，but the effect of different concentrations was varied，among which the effect of 0.3 g ? kg-1 was the most significant. Compared with the control，plant height，ground diameter，fresh weight and dry weight of M. hupehensis Rehd. that was treated by 0.3 g ? kg-1 of sulfur increased by 60.83%（26.03%，the data from open-field pot，the same below），26.78%（19.66%），73.44%（62.15%）and 93.32%（72.93%），respectively；root length，root surface area，root volume，number of root tips，and root respiration rate of M. hupehensis Rehd. increased by1.47（1.82），2.28（2.05），2.05（2.74），1.73（1.67）and 2.12（1.98）times. The chlorophyll content，photosynthetic parameters of the leaves and soil enzyme activities were increased in different degrees after sulfur treatment. 0.3 g ? kg-1 sulphur treatment had the highest bacterial to fungal ratio，the fungal margalef and shannon index，and the lowest fungal simpson index. Principal component analysis found that with the increase of sulfur addition，the distance of soil fungal community was farther and farther away from the control，but the continuous increase of sulfur content from 0.3 to 0.5 g ? kg-1 did not have a significant effect on the improvement of continuous cropping soil environment. The results of real-time fluorescence quantitative analysis showed that the addition of sulfur significantly reduced the copy number of Fusarium oxysporum gene. In conclusion，0.3 g ? kg-1 sulfur treatment can better optimize apple replanted the soil environment and promote the growth of M. hupehensis Rehd. seedlings，which can be used as an effective method to alleviate the apple replant disease.

Key words: Malus hupehensis, apple, replant disease, sulfur