This paper introduces basic knowledge and morphological types of roots which reveal that buttress roots, ground roots, aerial roots and brace roots are all unique root-modifying of tropical rainforest plants in Xishuangbanna and which constitute unique tropical rainforest landscape such as single-tree forest and plant strangler and so on and points out that the root-modifying of tropical rainforest arbor are the laws for the plants to survive by competing the space and by suiting the environment,