To separate anticaries and antiinflammation from Aloe vera peel, we investigated a inhibited effect of Streptococcus mutans JC-2 that was antibiosis, glucosyltransferase activity about aloe-emodin and barbaloin. Aloe-emodin and barbaloin had strong antibiosis activity against Streptococcus mutans JC-2, they were especially antibiosis effect to low growth and prolong lag phase at attachment concentration 100$mu extrm{g}$/mL. The reduction rate of a culture fluid became to lessen than the comparison group for aloe-emodin and barbaloin. The intracellular materials of Streptococcus mutans JC-2 were to leakage as much as attachment concentration addition of aloe-emodin and barbaloin but there was no significant difference membrane demage between two active substances. The activity of GTase was inhibited by aloe-emodin and barbaloin and their inhibition rate was respectively 99.8%, 98.4% at the attachment concentration 100$mu extrm{g}$/mL.