In this study, the reserve was divided into six vegetation vertical zones ［steppe zone (1 800-2 000 m), mountain scrub zone (2 000-2 200 m), subalpine coniferous forest zone (2 200-2 900 m), subalpine dwarf forest zone (2 900-3 000 m), alpine scrub zone (3 000-3 500 m) and alpine meadow zone (>3 500 m)］ according to the altitude gradient by field survey and collection of relevant literature, On the basis of the plant lists of the six vegetation vertical zones, we used seed plants as the study objects to analyze the seed plant richness, life type, zonal composition and phylogenetic structure of each vegetation vertical zone, and to explore the vertical change pattern of plant diversity along the elevation of the vegetation vertical zones, with the aim of understanding the ecological adaptability of plants to the environment. The aim was to understand the ecological adaptability of plants to the environment and to provide a theoretical basis for the conservation and exploitation of plant diversity in mountainous areas. The results show that: (1) According to the latest classification system, the seed plants of Xinglong Mountain Nature Reserve belonged to 87 families, 387 genera and 889 species, and the richness of plant families, genera and species followed a unimodal distribution pattern with the elevation of the vegetation vertical zone, reaching a peak in the subalpine coniferous forest zone (81 families, 304 genera and 661 species); the Jaccard similarity coefficient among the vegetation vertical zones was moderately dissimilar and extremely dissimilar. The higher the similarity coefficient between vegetation vertical zones, the closer the altitude was to the vegetation vertical zone. (2) There were differences in the pattern of vertical variation in the different life types of seed plants in the reserve, with the proportion of woody plants increasing and then decreasing along the elevation of the vegetation vertical zone, while the herbaceous plants showed the opposite variation pattern, and the proportion of herbaceous plants in each vegetation vertical zone was always higher than that of woody plants. (3) Seed plants of the reserve at the genus level, the proportion of tropical components in protected areas tended to decrease as the elevation of vegetation zones increases, while the proportion of temperate components tended to increase. (4) The phylogenetic structure was dispersed in the subalpine coniferous forest zone at middle and low altitudes, and aggregated in the three vegetation zones at high altitudes (>2 900 m), indicating that the non-random distribution pattern of the Xinglong Mountain Nature Reserve played a major role in the community construction mechanism.