Abstract: To provide a theoretical basis for vegetation restoration and the maintenance of biodiversity, we studied the effects of the duration of enclosure on plant propagation and vegetation regeneration in the semiarid perennial steppe of Yunwu Mountain. We compared non-enclosed (grazed) grasslands and grasslands enclosed for 5, 15, 23, 32 years using the field root-digging method to investigate plant reproductive strategies. The results showed that the duration of enclosure significantly affected species richness (P<0.05). Species richness was significantly higher in grazed sites than in grasslands with 23 and 32 years of grazing exclusion. However, there was no significant difference in species richness among grazed grassland, grassland with 5 years grazing exclusion, and grassland with 15 years grazing exclusion (P>0.05). The duration of enclosure significantly affected the densities of total offspring, asexual offspring, rhizomes, tillers, stolons, and branches (P<0.05), however, the densities of sexual offspring and root suckers did not differ significantly among the treatments (P>0.05). With prolonged duration of enclosure, the total density and asexual reproduction density decreased; the offspring density from rhizomes and tillers first increased and then decreased; the offspring density from root suckers and branches first decreased and then increased; the offspring density from stolons increased gradually; and the ratio of asexual and sexual reproduction densities first increased and then decreased. There were significant positive correlations between vegetation density and asexual offspring density, and between vegetation density and total offspring density. Our results indicate that short-term enclosure was conducive to offspring recruitment, and long-term enclosure was disadvantageous for grassland regeneration. Fencing for 5 years was the most conducive to offspring recruitment and grassland regeneration in the semiarid steppe of Yunwu Mountain. Compared with sexual offspring, asexual offspring contributed more to total offspring density, which directly affects the density of the plant community. The trends in the change in density in the plant community could be predicted from offspring density during the succession process.