【Objective】 The study aims to investigate the morphological adaptation characteristics of tree peonies growing in different habitats to the environment of the plains, and to provide references for research on conservation measures of tree peonies and screening of excellent germplasm resources. 【Methods】The Central Plains tree peonies （Paeonia ostii 'Fengdan' and 'Luoyanghong'）and wild tree peonies（P. delavayi Franch，P. potanini，P. ludlowii，P. lutea Franch，P. lutea and P. qiui）in different habitats were used as experimental materials, and the anatomical structure of the leaves was observed by paraffin section technique and the relevant indexes were determined and analyzed. 【Results】（1）The upper and lower epidermal cells of the leaves of the Central Plains tree peonies and the wild tree peonies were irregularly shaped, the stomata were uniformly distributed in the lower epidermis, and the morphology of the leaf epidermis showed different degrees of variability. （2）The leaves of both the Central Plains tree peonies and the wild tree peonies were heterofacial, and there were significant differences in the anatomical structure and photosynthetic pigment content of the leaves of different tree peonies. P. ludlowii has characteristics of wet plants, such as relatively thin leaf blade and cuticle, undeveloped fenestrated tissues, large cell gaps and maximum stomatal density; P. lutea has the greatest thickness of leaf blade, fenestrated tissues and spongy tissues, and shows strong adaptability to the high temperature and partial aridity of the plain habitat. （3）There were highly significant positive correlations between leaf thickness and upper epidermal thickness, fence tissue thickness, and spongy tissue thickness. There were highly significant positive correlations between stomatal long axis, stomatal index and traits such as fence tissue thickness and leaf thickness. 【Conclusion】All the germplasm of wild tree peonies except P. ludlowii is well adapted to the high-temperature and arid plains habitats, and the indicators of wet structure and photosynthetic pigment content of P. ludlowii can be the main reason why it cannot be cultivated in the plains.