Abstract: The biological control effects of ethanol extracts of Perilla frutescens on Myzus Persicae were investigated by chemical analysis and bioassay methods. The results showed that the effects of ethanol extracts of P. frutescens on M. Persicae were significant across the experimental conditions. The indoor experiments showed that the relative bioactivities against M. Persicae of the extracts were stronger at the concentrations of 9 g and 7 g DW/100 mL. The antifeeding rates that caused by the use of the two extracts with the highest bioactivities were 64.64% to 79.34% for the 9 g DW/100 mL extract and 51.24% to 61.24% for the 7 g DW/100 mL extract. The deterrent rates were over 58.43%. The corresponding mortalities caused by these extracts were over 83.83%. In the field experiments, the interference effects of ethanol extracts of P. frutescens on M. Persicae were obvious. The antifeeding rates of the 9 g DW/mL and 7 g DW/100 mL extracts were 53.45% and 65.56% respectively. The population control interference index values of these two extracts were 0.468 and 0.367. These results indicate that the ethanol extracts of P. frutescens have great biological control effects on M. Persicae and that P. frutescens could be used as a latent material in developing an effective agent for protecting tobacco.