Abstract: This paper deals with an anatomical study of the secondary xylem of H. rharnoides from different habitats using light microscope (LM) and SEM. It gives a detail description of the general characteristics of the constitutions of the secondary xylem of the plant. By taking the ten major quantitative characteristics of the secondary xylem of H. rhamnoides-vessel frequencies of early wood and late wood, percentage of solitary vessels, tangential vessel diameter, vessel member length, fibre-tracheid length, ray frequency and ray height--as indicators. Male and female plants have been made a comparison under the same or different habitats. The results of observation showed that the change in habitat showed no effects on the structure of the secondary xylem of H. rhamnoides except that there were some effects on some quantitative characteristics. This paper also makes a survey of the effects of rainfall and sex on thte structure of the secondary xylem of H. rhamnoides.

Key words: Hippophae rhamnoides L., Different habitats, Xylem anatomy