Microbial transformation of cardamonin by Mucor spinosus (CGMCC 3.3450) in preparative scale resulted in the isolation of two new products. Their structures were elucidated unambiguously by ESI-MS, 1H NMR, 13C NMR and 2D NMR spectra analyses as 4-O-beta-D-glucopyranosyl-6-hydroxy-2-methoxychalcone (1, 4-GluC) and 6-O-beta-D-glucopyranosyl-4-hydroxy-2-methoxychalcone (2, 6-GluC), respectively. The time-course of biotransformation by M. spinosus showed that both 4-GluC and 6-GluC appeared on the 2nd day. The optimal biotransformation temperature was 28 degrees C, the optimal biotransformation time was 72 h and the optimal concentration for cardamonin was 40 mg x mL(-1). This is the first time for successful microbial glycosylation of cardamonin in present research.