A field experiment system was established to study the interaction between Solanum melongena L. and Tetranychus cinnabarinus Boisduval with emphasis on plant stress reaction mechanism under pest pressure. It was discovered and proved for the first time that piercing-sucking of T. cinnabarinus could induce accumulation of HRGP, a structural protein of plant cell wall in S. melongena leaves. This induced response has certain characteristics similar to other induced responses; e.g. the induction could be transmitted in the plant with temporal dynamics and its strength was correlated with the extent of injury. Observations on the activity of GDH enzyme showed that plant stress reaction was a combination of various physiological metabolic reactions which constitutes the self-regulative and integrated defense process of plants.