After one branch needles of potted plant Pinus massioniana was fed by Dendrolimus Punctatus, the composition and relative contents of volatile organic compounds (VOCs) from the adjacent upper branch needles of insect-damaged branch at different times was analyzed by TCT-GC/MS. The results showed that terpenes were the dominant, while the others such as oxygenated and nitrogenous compounds were less abundant VOCs. Most of VOCs in treated plants had higher contents than those in the control after 1 h treatment and remained much high levels at 2 h. The content of methyl jasmonic acids (MeJA) in adjacent needles of infected Pinus massioniana was increased after 1h treatment and nearly doubled that of control plants at 2h. The data indicates that the defensive system of Pinus massioniana was initiated and leading to the resistance reaction of the neighborhood undamaged branches by inset-pest.