Abstract: Objective To explore relationship between the pathological T-staging and the gross tumor volume (GTV) of esophageal cancer by CT scanning and provide the reference for clinical T-stageing of esophageal carcinoma. Methods Two hundred and eight patients with esophageal cancer have received operation from January 2005 to December. They all were checked by CT scanning on chest before operation. GTV-T target was delineated by applying 3D radiotherapy system. The largest diameter and the lesion of esophageal affection were measured for each case, and GTV-T volume was calculated. Recorded and measured the lesion length of esophageal cancer in operation. Analyze the relation-ship of the GTV-T volume, the maximum diameter, the length of lesion and the pathological T-staging. Results There was no significant difference between the length of GTV and the lesion length measured by in-operation of esophageal cancer （t=-1.786,P=0.076）.The GTV-T volume of T1 stage was significantly different compared with T2, T3, T4 stage (P<0.05), as same between T2 and T3 stage in GTV (P<0.05). But the GTV was not different between T2 and T4 stage, T3 and T4 stage. About the lesion length and the maximum diameter, T1 stage was significantly different with T3, T4 stage (P<0.05). There was no difference between T1 and T2 stage. Furthermore, T2 stage was dramatically different with T3 and T4 stage in the maximum diameter and length of esophageal lesion (P<0.05), but no difference between T3 and T4 stage. Conclusion The later pathological T-stage is, the larger tumor volume is. The GTV-T volume of esophageal cancer might be used as guidance of esophageal cancer clinical T stage.