A glycolipids type biosurfactant, as identified by FTIR was obtained from Enterobacter cloacae, a petroleum-degrading bacterium. The optimum productivity of the biosurfactant was obtained. An optimal yield of biosurfactant was achieved at a n(C)/n(N) ratio of 8.9 using glucose as carbon source and ammonium chloride as nitrogen source when the initial pH value of the culture media is 7.2. It is shown that the presence of the biosurfactant greatly enhanced water-solubility of phenanthrene and the removal of phenanthrene from kaolinite soil. These would thus improve the bioavailability of phenanthrene and intensify the bioremediation of petroleum contaminated soil.