Compound K(ginsenoside M1) is one of saponin metabolites and has many benefits for human health. This study was to investigate Compound K produced from ginseng crude saponin extract with commercial cellulolytic complex enzyme(cellulase, β-glucanase, and hemicellulase) obtained from Trichoderma reesei. The effect factors(temperature, pH, ginseng crude saponin extract and enzyme concentration, and reaction time) on production of Compound K from ginseng crude saponin extract were determined by one factor at a time method. The selected major factor variables were ginseng crude saponin extract of 2%(w/v), enzyme of 7%(v/v), reaction time of 48 hr. Based on the effect factors, response surface method was proceeded to optimize the enzymatic bioconversion conditions for the desirable Compound K production under the fixed condition of pH 5.0 and 50℃. The optimal reaction condition from RSM was ginseng crude saponin extract of 2.38%, enzyme of 6.06%, and reaction time of 64.04 hr. The expected concentration of Compound K produced from that reaction was 840.77 ㎎/100 g. Production of Compound K was 1, 017.93 ㎎/100 g and 862.31 ㎎/100 g, by flask and bench-scale bioreactor(2.5ℓ) system, respectively.