Objective：To determine the relationship between EGFRvⅢ expression and sensitivity of SKOV3 cell to Gefitinib and to give rational guidance to clinical medication. Methods：Plasmid pcDNA4/TO-EGFRvⅢ was stably transfected into SKOV3 cell and the cell strains stably expressing EGFRvⅢ were screened out by zeocin antibiotics and named SKOV3-EGFRvⅢ. MTT was used to assess the viability of SKOV3- EGFRvⅢ cell and SKOV3 cell treated by Gefitinib. Nude mice allograft tumor models bearing SKOV3 and SKOV-EGFRvⅢ were treated by Gefitinib. The sensitivity of the tumor model to Gefitinib was assessed by measuring the tumor size. Results：Results of Western blot indicated that SKOV3-EGFRvⅢ cell strain was successfully established. According to the results of MMT，after being treated by Gefitinib，the mortality was lower in SKOV3-EGFRvⅢ cell than in SKOV3 cell and the inhibi－tion effect of Gefitinib was less intense on tumor model carrying SKOV3-EGFRvⅢ cell than on that carrying SKOV3. Conclusion：Over expression of EGFRvⅢ in ovarian cancer SKOV3 cell results in its decreased sensitivity to Gefitinib.