Abstract: In order to investigate the indoor biological activity and practical application value of methyl palmitate，the bioactivity of phytophagous mites contacting with methyl palmitate were studied. Methyl palmitate was demonstrated to have acaricide and repellent effect on adult carmine spider mite Tetranychus cinnabarinus. There were synergetic effects of the industrial methyl palmitate and Silwet L-77 on contacting adult T. cinnabarinus. The better paired compounding between methyl palmitate and Silwet L-77 were 8 mg/mL×200 μL/L, 5mg/mL×400 μL/L and 8mg/mL×400 μL/L. These mixing ratio would provided evidence for acaricide production.