The fumarase from the culture of Aspergillus wentii F-871 was partially by means of precipitation with protamine sulphate, ammonium sulfate fractionation and column chromatography on Sephadex G-200, and then the concentrated enzyme solution was freeze-dried. The comparative enzyme activity of the fumarase was increased by 31.70 times and reached 24.6 U/mg, and the recovery was 36.64% . The optimal pH and temperature was 8.0 and 30℃, respectively. The pH stability of fumarase ranged 6.0 - 8.5, and more than 90% of the enzyme activity remained after incubated at 35℃ for 30 min.