Abstract： Objective　To optimize the oral contrast media in three-dimensional display of gastric lesions. Methods　41 cases were randomly divided into 3 groups according to different oral contrast media administered: No. 1 air contrast group (n=17), No. 2 fat emulsion group (n=7) and No. 3 positive contrast group (n=25). The 3D CT images were reconstructed using MPR, SSD, RaySum display and virtual endoscopic techniques, and compared with gastric endoscopy and/or conventional barium study.Results　The detectability of gastric lesions using fat emulsion and air contrast was 42.8%(3/7) and 80.0%(20/25), respectively, both were significantly lower than that using positive contrast (100%, 30/30) (χ2=19.22,P＜0.01;χ2=6.60, P＜0.05). The capability of showing the details of stomach lesions was significantly affected by the oral contrast media administered（χ2=17.04，P＜0.01）. Conclusion　It is very important to choose the appropriate oral contrast media for 3D display of gastric lesions in spiral CT, the positive contrast agent is the optimal choice.