The majority of citrus trees in Hwangyen district,Chekiang province,are planted on the alluvial soils.These soils are partially in poorly drained condition.Citrus trees occur also on yellow earth and red earth of the same district with a comparatively higher elevation.Microelements in the soils have been determined by polarographic and colorimetric methods.Results show that they contain Cu 1.1-4.1 ppm.,Zn 1.7-64.0 ppm.,Ma 5.6-260 ppm.,Mo 0.02-0.08 ppm.and B 0.4-3.3 ppm.