The aseptic seedlings of Albizia julibrissin were divided into two groups. One group was inoculated by rhizobia and the other was designed as control without inoculation. These two groups were all cultivated in sterilized cultured liquid for about two weeks. In the first group,the root hairs did not form on the main roots,but formed a lot on the base part of the lateral roots. In the second group, the root hairs did not form not only on the main roots but also on the lateral roots. The root segments which have distinctive deformation of root hairs from first group were cut off and fixed, in the meanwhile the corresponding root segments were cut off from the contrastive group and fixed. These two groups of roots segments were treated as semi-thin section and ultrathin sections, then were observed by optical microscope and transmission electron microscope. The result showed that the transfer cells with wall ingrowths on the tangential exowall of the root’s epiderm and exodermis cells, are easy to be found in the root segments which has distinctive deformation of root hair. The wall ingrowth lies not only in root epidermal cells but also in the root exodermis cells, while there is no wall ingrowth in root epiderm and exodermis cells of A. julibrissin which is not inoculated by rhizobia. This suggested that the forming of root hairs and transfer cells in epiderm and exodermis of A. julibrissin is resulted from the inducement of rhizobia of A. julibrissin.
