In a 0.2N hydrochloric acid medium, new color reagent p-Iodochlorophosphonazo （p-ICP） sharp reacts with rare earths form the blue-violet complexes. Absorption maximum of lighter rare earth complexes （La to Gd） are at 685nm and absorption maximum of heavier rare earths complexes（Tb to Lu Y） are at 675nm. Under the certain experimental conditions the apparent molar absorptivity of rare earths complexes are very much the same being （8.7-10.8）×10,4,·mol,-1,·cm,-1,. To the test containing 1ml 1.227×10,-4,M rare earths, 5ml of 1N hydrochlorie acid, 2ml 0.05% p-ICP are added in proper order. Then the solution is diluted to 25ml with water, against the reagent blank. Beer’s law is obeyed over o-20μg RE/25ml. The absorbance of complex was stable for at least 6 hours. As the result of the equilibrium shift method the molar ratio of Lanthanum to p-ICP in the complex is estimated to be 1: 2. Ammonium fluoride is used for masking reagent the micro-amount of rare earths in the soil was determined by this method.