Abstract: The effects of magnesium（Mg），iron（Fe）and boron（B）deficiency on growth and physiological characteristics in shoots and roots of four citrus rootstocks{Trifoliate orange[Poncirus trifoliate（L.）Raf.]，Fragrant citrus（Citrus junos Sieb.ex Tanaka），Red tangerine（Citrus reticulate Blanco）and Congyi wild mandarin（Citrus reticulata）} were investigated by using hydroponic culture. Results indicated that the plant height，total leaves，chlorophyll content，total roots length，total roots surface and Mg specific absorption rate were better in red tangerine than those in other rootstocks under the treatment of Mg deficiency. In the treatment of Fe deficiency，the plant high，total leaves，dry weight of plant，total roots volume，total roots surface and Fe specific absorption rate were better in fragrant citrus than those in other rootstocks. In B deficiency treatment，the roots number of tips，total roots surface，total roots volume and B specific absorption rate in Red tangerine and the plant high，total leaves and dry weight of shoot in Congyi wild mandarin were better than those in other rootstocks，respectively.

Key words: citrus, rootstock, hydroponic, Mg, Fe, B, deficiency