Lactosucroses (4G-β-Galactosylsucrose) have attracted attention in response to an increasingdemand for so-called health foods with functional properties such as calorie free, non-cariogenic, decreasing the total cholesterol and lipid in serum, the promotion of animal growth and improving the intestinal bifidobacterium. They are produced from sucrose and lactose by the action of β- fructofuranosidase (EC 3.2.1.26) producing from various microorganisms such as Arthrobacter sp, sprobomyces sp etc. The objective of this study is to optimize the culture medium and conditions for the production oflactosucrose by Sterigmatomyces elviae mutants. And continuous production using whole cell enzyme immobilization was carried out with aim of obtaining a high productivity of lactosucrose. Optimized media for the lactosucrose production using statistical experimental design and were determined to be 1.21 % sucrose, 0.98% yeast extract, 2.92% bactopeptone and 0.536% ammonium sulfate. Then, the carbon source and ammonium sulfate have an important effect on the production of lactosucrose. The optimized culture conditions were determined to be 10% inoculum size, pH 6.5 and 50℃.