Objective To investigate the intervening effect of Qi-Boosting Toxin-Resolving Formula (QBTRF) on the migration potentiality of nasopharyngeal carcinoma (NPC) cells and its association with the expressive activities of cellular skeletal protein system based on an experimental study in vitro.Methods In this study,QBTRF medicine-containing plasma of rats was taken as the intervening factor to treat the targeted NPC cells of CEN2Z for evaluating the correlation of changes in migrating potentiality of CEN2Z cells with expression activities of cellular skeletal protein system and their response to the pharmacological intervening effects of QBTRF,compared with the normal plasma of rats as the control.Here,scratching test was taken to evaluate the migration potentiality of targeting cells,immunohistochemical SABC assays were used to determine the expression activities of β-tubulin,F-actin,p-Ezrin and Rac1,which were taken as the typical indicators of cellular skeletal protein system.Scanning electron microscopy was selected to observe the changes in cellular pseudopodia.Reverse transcription-polymerase chain reaction (RT-PCR) procedure was used to detect the transcriptional activity of p-Ezrin mRNA.Results QBTRF showed a very significant inhibitory effect on the migration potentiality of CEN2Z cells,with its migration distance reduced to (25.80 ±8.07) μm and an inhibitory rate reached at 46.59％ at the concentration of IC50.Meanwhile,their cellular pseudopodia was shortened significantly,accompanied with very reduced extension length.Obviously decreased were the expression activities of β-tubulin,F-actin,p-Ezrin and Rac1 proteins,with their figure gray values being 0.857 ±0.059,0.900 ±0.040,0.812 ±0.050 and 0.785 ±0.022,respectively,with statistical significance compared with controls (P ＜0.01).Also seen was the same tendency of transcriptional level of p-Ezrin mRNA when cells cultured with QBTRE medicines-containing plasma together.Conclusions QBTRF holds significantly inhibitory effect on the migration potentiality of CEN2Z NPC cells.This kind of inhibitory effect may be associated with the reduced biological activity of cellular skeletal protein system and corresponding cellular pseudopodia changes.