Abstract: This study discusses the adaptability of introduced plant species to their target environment at Xishuangbanna Tropical Botanical Garden (XTBG), Chinese Academy of Sciences (CAS) by comparing the growth situation, especially fruit ripening of introduced plants and indigenous plants. Over 10 , 000 plant species from tropical and subtropical regions have been planted at XTBG, and many of these plants’growth situations have been continuously observed. In this paper, 569 accessions which have been observed for more than four years are involved. The results show that: 1) the introduced plants primarily adapt the environment at XTBG. However, the plants from different climate regions show different adaptability. The adaptability order is: tropical Asia > northern edge of tropical Asia and subtropical area, tropical Africa > tropical Australia > tropical America. 2) Different families and genera of introduced plants show different adaptability to the target environment too. Some introduced plants belonging to the families of Sapinaceae, Papilionaceae, Meliaceae and Bignoniaceae etc. adapt well to the target environment at XTBG, while some plants of Euphorbiaceae do not adapt well to the target environment. Some introduced plants of Bignoniaceae,
Myrtaceae and Mimosaceae exhibit more frequent fruit ripening than the indigenous plants . Analyses show that the climate and flora of the origins of introduced plants are the major factors influencing the adaptability of the introduced plants to the target environment at XTBG. Further study needs to be done to assess the invasion of these plants.

Key words: Adaptation