Abstract: Pepsinogens (PGs) which consists of two types: pepsinogen I (PGI) andpepsinogen Ⅱ (PGⅡ)  are the precursors of pepsin. In patients with gastric mucosal atrophy,the serum concentrations of PGI and PGⅡ decrease with the development of atrophy. PGI has a more obvious decrease than PGⅡ, so the PGI/Ⅱ ratio is lower. Low PGI, low PGI/Ⅱ ratio, or  low values of both are good serological indicators of atrophic gastritis. Gastrin 17 (G17)  is produced by G cells in the antrum. Serum G17 concentration depends on the intragastric acidity and the number of G cells. G17 can detect atrophic gastritis limited to the antrum (low G17 concentration) or the corpus (high G17 concentration). The combination of PG and G 17 is a useful tool for the diagnosis of atrophic gastritis, applied to the gastric cancer risk stratification and screening of  high  risk populations, with the higher sensitivity, specificity and negative predictive value(74.7%, 95.6%  and  91%, respectively). But, serum PG and G17 concentrations are affected by Hp, PPI use, age,  gender and other factors.

Key words: gastritis, , atrophic；pepsinogens；gastrins；diagnosis