1.Results of analysis of the soils, leaf diagnosis of citrus and field experiment of the citrus orchards in Guangxi showed that soils developed from old diluvium, sandy shales, red sandstones, fluvial deposits and limestone talus wide-spread in this district were geneally poor in mace elements Zn, B and Mo.2.The contents of available Mo, Zn, Co, Mn, K, Ca and Mg in soils were positively correlated with those in citrus leaves.Zn deficiency symptom was found clearly incitrus leaves,while available Zn was less than 0.50 ppm in soils and less than 15 ppm in citrus leaves.3.Reasonable application of micronutrients (B, Zn, Mo) was conducive both to increase the yield and improve the fruit quality of citrus.