Abstract: Objective To explore the differences between 1992 Fuzhou staging and 2008 staging system，between computed tomography (CT) and magnetic resonance imaging (MRI)scans of the lesion detection，the impaction to primary tumor volume of nasopharyngeal carcinoma(GTV) and volume calculation. Methods Eighty-nine nasopharyngeal carcinoma cases with new-treated CT and MRI images were collected，staging the T，N stage respectively in 1992 Fuzhou and 2008 staging system，comparing the differences between the two means of checking the detection.Thirty-nine cases with differences between CT and MRI imaging were selected to draw the target volume of primary tumor and calculate the volume under the treatment plan system(TPS). Results Because MRI images in 1992 Fuzhou staging，the composition of early(T1+T2) was lower than the increased ratio of late(T3+T4).The 2008 staging increased T3，T4 patients.In T2 and T3 stage division，the two phases have significant difference (P=0.033，0.008)，the difference of N1，N2 was statistically significant(P<0.05).MRI was better than CT in detecting the invasion of NPC in head long muscle，parapharyngeal space，cavernous sinus，paranasal sinuses and cranial nerves.In displaying lymph nodes in retropharyngeal，the neck shape，capsule，necrosis and fusion，MRI was superior to CT.For target of the 39 cases of CT and MRI images outlined，the results showed GTVMRI>GTVCT. Conclusion According to MRI images of 1992 Fuzhou staging，we find more advanced cases，the need for comprehensive treatment(radiotherapy+chemotherapy)patients has increased，the choice of treatment provides an important reference.With MRI-based 2008 stage system is the main criterion guiding the treatment of nasopharyngeal carcinoma.MRI images of images can effectively avoid the misdiagnosis of the tumor tissue and normal tissue，both enhancing local control and protecting normal tissue，the nose pharyngeal cancer patients will be treated advantageously.