The microorganism which is able to grow in oil was isolated and identified. This microorganism was identified as Mucor sp. and accumulated lipase in culture fluid. The factors affecting growth and lipase production by Mucor sp. has been investigated. Mucor sp. showed maximum lipase production at $30\,^\circ\!C$ and at PH 7.0 in 3days. Aeration stimulated the growth and lipase production. The medium supplemented with olive oil stimulated the maximum production of lipase, whereas carbohydrate reduce the growth and remarkably decreased the lipase production. Among the nitrogen sources tested, soy bean meal yielded maximum lipase production at 2\%. The extacellular lipase was purified treating the ammonium sulfate precipitation, and applying the chromatography on Sephadex G-200 and Sephadex G-100 columns. The enzyme was purified 52 fold with the yield of 18\%. The enzyme showed its optimum PH and temperature at 7.0 and $30\,^\circ\!C$, respectively. The enzyme activity was enhanced slitely by $CaCl_2$, while $ZnCl_2$, $FeCl_3$, and $HgCl_2$ were inhibitory. The bile salts showed either an activating or inhibiting effects, depending on the concentration. The effect of organic solvent on the stability and catalytic activity of the Mucor lipase has been examined. The solvents examined were 5 hydrocarbons and 3 ethers. The result revealed that isooctane is superior to the other solvents examined. Among the triglycerides tested, triolein was hydrolyzed most easily by the enzyme as compared with tributyrin and triacetin.