Abstract: It has been shown in previous articles^[1,2], that yellow powderly tungstic acid is not merely a metathetical product between a tungstate salt with an acid. Its formation involves a series of consecutive reactions, in which complex tungsten ion is an intermediate form. Improper regulation of conditions^[3] will invariably result in admixture of impure white tungstic acid,revealed in its slow dissolution in cold ammonium hydroxide solution, different from the ready solution of the yellow powdery form.When sodium tungstate solution is acidified by dropwise addition of any acid, white tungstic acid will appear due to local reaction. It is curdy in form, and is incapable of being isolated on account of its succeeding reaction with existing tungtates in solution. M. L. Freedman^[4] at 1959 was however able to isolate white tungstic acid (C-Phase) in virtually powder form. But Na was still found present in small amount, which indicated the occulation of certain gelatinous form. The yield was also low, only 30%.On recognizing the definite presence of white powderly tungstic acid as a distinct species, and after considering the possible mechanism for its formation, we were enabled to design a procedure for the preparation of pure white powderly tungstic acid in rather high yield. This involves using low acidity, room temperature, an acid with low ability to form complex ion of tungsten, prevention of colloid formation as well as its peptization, and most important of all, the "reversed way of acidification", i.,e., addition of sodium tungstate solution to a dilute acid solution.Filtration and washing were rapid; the filtrate was clear. After washing with pure water, final hashing with ethyl alcol or acetone enabled the removal of adsorbed water, so as to prevent the gradual discoloration of the white powder to faint yellow. The yield after drying at room temperature was 95%.