Production and properties of invertase from. Aspergillus niger were investigated. Inuli and sucrose were best carbon source and yeast extract was most suitable for the production of the enzyme among tested carbon and nitrogen sources. The enzyme was maximally produced by cultivating the organism at medium of pH 4.5 and temperature of 3$0^{circ}C$ The optimum pH and temperature for the enzyme activity were pH 5.0 and temperature of 5$0^{circ}C$ respectively Among tested metal ions Hg2+ Cu2+ and Ag+ ions inhibited the enzyme activity drastically.