Abstract: In order to lower the consumption of acid and alkali and to simplify the process for refining low temperature coal tar fractions, the phenolate extraction process was studied. In this work the influences of the concentrations of NaOH solutions and that of the contents of phenols in the coal tar fractions on the effectiveness of extraction, the quantity of NaOH required during countercurrent extraction, the quantity of water required to dilute the saturatedphenolate solutions there by obtained for the separation of the dissolved phenols, and the physico-chemical properties of the refined oils and that of the crude phenols were studied. The experimental results have shown that, in the phenolate extraction process only 10-15 kg of NaOH is required to extract 100 kg phenols from the coal tar fractions. The quantity of NaOH is much less than that required in the ordinary alkali extraction process, where 40-45 kg. of NaOH is required to extract 100 kg phenols. The refined oil can be used as diesel fuel without further refining. The phenols of higher b. p. and of lower b. p. can be separated by dilution of the extracts. It was also observed that an accompanied effect of lowering the S and N contents of the fractions appears significant. The results of engine tests of the refined oil in diesel engines of 1200 and 2500 r. p. m. have shown that the quality of the oil is satisfactory.