Abstract: The effect of addition of absorbent resin on the preparation of (S)-1-phenyl-1,2-ethanediol (S-PED) from racemate by stereoinversion was investigated, with whole cells of Candida parapsilosis as catalyst. To increase the substrate concentration in reaction, absorbent resin NKAⅡwas selected, which had a relatively high adsorption amount and velocity to both substrate and product. By adding NKAⅡadsorption resin in the reaction system, substrate and or product inhibition was mitigated, and the initial substrate concentration was thus increased. According to adsorption capacity and optimal substrate concentration of reaction, a formula was established about the resin addition amount along with the change of substrate concentration. According to the formula, the PED concentration in aqueous phase could be controlled at a best level. Thus, high substrate concentration and high reaction speed could be achieved. Then 0.74 g NKAⅡ adsorbent resin was added to the system at an increased substrate concentration of 40 g/L with a pre-adsorption for 2 h before reaction. When reacting for 108 h under optimized conditions, the optical purity and yield of (S)-enantiomer reached 98.1% and 88.5% respectively, with the product concentration of 35.4 g/L.