Abstract: Exploring the impact of artifical forest on species diversity within nature reserve can provide guidance for improving avian habitats and advancing biodiversity conservation. A comparative survey was conducted across 23 plots in a typical Larix kaempferi plantation and adjacent secondary shrubland within the reserve to assess species diversity and its influencing factors. The research results indicated that: 1) A total of 45 plant species belonging to 42 genera and 25 families were recorded in the 13 plantation plots, whereas 61 species in 56 genera and 39 families were found in the 10 secondary shrubland plots. 2) Compared with the secondary shrubland, the plantation exhibited markedly lower species richness; its tree layer was dominated by only two species — L. kaempferi and Pinus massoniana. 3) All four diversity indices (Shannon-Wiener, Simpson, Pielou and Margalef) for the tree layer, as well as the Shannon-Wiener, Simpson and Margalef indices for the shrub layer, were significantly lower in the plantation than in the secondary shrubland. 4) The four tree-layer diversity indices and the herb-layer Pielou index were significantly positively correlated with soil total potassium; all four indices in both the tree and shrub layers were significantly or highly significantly positively correlated with soil pH; and the Shannon-Wiener, Margalef and Simpson indices of the shrub layer were highly significantly or significantly positively correlated with elevation. The artifical forest markedly reduced vegetation species diversity, and the total potassium and pH of soil, and elevation was the principal environmental drivers of biodiversity. It is suggested that the artifical forest should be reformed and the shrub vegetation should be gradually restored to enhance species diversity.