Purpose:Despite the declining trend of stomach cancer incidence, it is still the second important cancer in China and ranks first in Yangzhong City. We examined the role of green tea consumption on stomach cancer and chronic gastritis risks by case control study. Interaction between green tea drinking and potential risk factors of stomach cancer and chronic gastrotitis were also explored. Methods:A population based case control study was conducted in Yangzhong, China, with 143 stomach cancer patients, 166 chronic gastitis patients and 433 healthy controls. Epidemiological data were collected by standard questionnaire, and blood samples were obtained for measurement of Helicobacter pylori infection. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression models. Results:Inverse association was observed between green tea drinking and stomach cancer and chronic gastritis risks. After adjusting for potential confounding factors, ORs of green tea drinking were 0.46 (95%CI: 0.22—0.96) and 0,46 (95%CI: 0.27—0.77) for stomach cancer and chronic gastritis, respectively. The less ORs of stomach cancer and chronic gastritis, the more frequent the green tea drinking ( P for trend