Introduction The ginseng saponin (ginsenoside) is one of the most important secondary metabolites in ginseng and hasvarious pharmacological activities. To date about 38 kinds of ginsenosides have been isolated and identified from Panax ginseng C. A. Meyer. Among these ginsenosides, Rg3 is a precursor for ginsenoside Rh2, which has a very strong antitumor effect. and has many pharmaceutical activities. However, Rg3 is extremely low in normal ginseng. Thus production of ginsenoside Rg3 would be very important and many studies have aimed to convert major ginsenosides to the more active minor ginsenoside Rg3. The enzymatic conversion through sugar hydrolysis at a specific position is desirable for the production of active minor ginsenoside Rg3. Material and Method The isolation of β-glucosidase-producing microorganisms was performed according to a previously published method. Each microbialsuspension cultured in nutrient broth was added to the same volume of 1 mM ginsenoside Rb1 solution and then incubated on a rotary shaker at 30°C for 48 h. The reaction mixture was extracted with butanol saturated with H2O and then analyzed by thin layer chromatography (TLC). 8 μl of the ginseng extract solution was spotted on a TLC plate and developed to 5.5 cm distance in a chamber with chloroform/methanol/water as the mobile phase. Bands on the TLC plates were detected by spraying 10% H2SO4, followed by heating. Result and Discussion Ginseng(the root of Panax ginseng C. A. Meyer, Araliaceae) is frequently used as a crude substance taken orally in Korea, China and Japan, as well as other Asian countries, as a traditional medicine. Ginsenosides are the principal components having pharmacological and biological activities. More than 38 different ginsenosides so far have been isolated and identified from ginseng saponins. Among them, deglycosylated ginsenosides are known to be more effective in vivo physiological action and to act as active compounds. A lactic acid bacteria, which have β-glucosidase activity, were isolated from soil and kimchi using a MRS-Esculin agar. These strains were identified on the basis of phylogenetic inference based on 16S rDNA sequences. TLC and HPLC were used to analysis transformed ginsenosides. Ginsenosides are main pharmacoactive component in ginseng. When ginseng was orally administered, the absorption of ginsenosides from the gastrointestinal tract are extremely low. In order to improve oral bioavailability, transforming major ginsenosides into more active minor ginsenoside is very important. Caulobacter leidyia GP45 and Micro- bacterium esteraromaticum GS514 were isolated from ginseng field for converting major ginsenosides into minor ginsenosides. In the co-culture of strain GP45 and GS514 with ginsenoside Rb1, produced compound K and ginsenoside Rg3 individually. The transformation pathway of ginsenoside Rb1 were confirmed Rb1⟶Rd⟶F2⟶compound K and Rb1⟶Rd⟶Rg3.