Abstract: The study on the yellowing mechanism of Chinese chestnut was carried out. Under the condition of water cultivation and absence of manganese and low content of ferrum (2 ppm), the edge of leaf turned yellow and then withered, and on the mesophyll appeared brown spots. When manganese was absentand concentration of ferrum was more than 10ppm, the whole plant withered todeath. If ferrum was absent and concentration of Mn was 30ppm, leaf becameyellow.In the experiment the plant grew well when the concentration of Mn and Fe was 10-50ppm and 10ppm respectively.Concentration of total ferrum in leaf decreased with the increase of Mn content in culture solution when the concentration of Fe was 2ppm in culture solution. If the concentration of Fe was 5.6 or 10ppm in the solution, total Fe content increased with the increase of Mn. The changing of chlorophyll was irregular with total ferrum concentration, but regular with concentration of active Fe and the value of Mn/Fe. When concentration of active Fe in leaf was more than 50ppm and value of Mn/'Fe was 1.0-1.5, content of chlo'rophyll was more than 3.00 mg/cm₂.

Key words: Chinese chestnut, Yellowing mechanism, Manganese, Ferrum