Six genus hybrids and their parents (Dimocarpus longan variety ‘Zaoshu’ ×Litchi chincnsis variety ‘Ziniangxi’) were used as test materials, the anatomical structures of xylem in root and stem were observed by manual microtomy and tissue segregation procedure, and the morphological characteristics, the organic nutrition and the photosynthetic rate of the tested materials were determined, and correlational analyses of the indexes were conducted. The results showed that the ratio of bark, ray width and vessel density of the hybrids were all less than those of the parents , and the vessel elements lengths of the hybrids were greater than those of the parents; except No 9 single plant, the diameter of vessel elements , the frequency of the vessel with tail in one end, plant height, stem diameter, leaf area, the length of internode were significantly greater than the parents, showed the obvious heterosis; in addition, the soluble, starch content, free amino acid content and the net photosynthetic rate of the strong plants of hybrids were greater than those of the weak plants; plant height, leaf area and internode spacing were high significant negative correlation ,with the bark rate and plant height was significant negative correlation with the bark rate; photosynthesis rate of hybrid was significant positive correlation with the ratio of total vessel area to xylem area, the diameter of vessel and the rate of vessel with tail in one end , but was negative correlation with the rate of vessel with tails in two ends; the soluble sugar content and starch content of the hybrid leaves were significant positive correlation with the ratio of total area to xylem area; the amino acid content was very significant or significant positive correlation with the diameter and length of the vessel element, but was negative correlation with the vessel density and ray width.