Chronic atrophic gastritis (CAG) is acknowledged as the precancerous stage of gastric cancer (GC). The present study aims to explore Traditional Chinese Medicine (TCM) syndrome features in different stages of CAG malignant transformation respectively. The proposed study is a cross-sectional study based participant survey conducted in 4 hospitals in Beijing, China. After obtaining informed consent, a total of 2000 study patients will be recruited on-site in hospitals.