Objective To assess the clinical significance of endoscopic ultrasonography (EUS) in the diagnosis and preoperative staging of gastric cancer. Methods EUS was carried out in 22 patients inclu-ding 17 gastric cancer patients and 5 patients in suspicion. Helical CT scanning was performed in all of the patients and fine needle aspiration biopsies ( FNAB) were administrated to 5 suspicious patients. Compared the results of operation and pathology with those of tumor staging by estimating the depth of tumor invasion ( T) , local lymph node metastasis ( N) and metastasis to neighboring or remote organs ( M) in order to esti-mate the accuracy of diagnosis and TNM staging. The sensitivity and specificity of tumor-node-metastasis staging of gastric cancer by EUS were compared with those of the spiral CT according to the final histopatho-logical results. Results In 5 suspicious patients specimens were successfully obtained by FNAB under the guide of EUS with the pathological diagnosis of adenocarcinoma in 4 cases and signet ring cell carcinoma, 1 case. All patients underwent radical gastrectomy except one in T1N0M0, staging was treated by endoscopic mucosal resection (EMR). The sensitivity and specificity of EUS in T, N, and M stage were 84.9% and 74. 2% , 92. 1% and 77. 1% , 63. 4% and 87. 5% respectively; whereas those of CT in T, N, and M stage were 27. 3% and 75% , 31.5% and 100% , 50% and 100% respectively. The sensitivity of EUS in T and N staging were higher than those of CT with significant statistical difference (P