Abstract: Objective :To explore the putative significance of serum pepsinogen (PG) level on the screening of the cardiac and esophageal carcinoma. Methods :The time resolved fluoroimmunoassay (TRFIA) was used detect the serum PG, and in combination with endoscopic biopsy and pathological observation in 133 patients, analyze contrastively the correlativity between the level of serum PG-I and-II, and the mucosal changes in the patients with chronic gastropathy, among which 94 cases with cardiac lesion and 39 with esophageal changes. Results :There was no significant difference in the median level of Serum PG I and PG II and PG I /PG II ratio in the patients with cardiac mucosal inflammation, precancerous lesions and cardiac adenocarcinoma, but the detection rate of the serum PG I <60N.,g/L in patients with precancerous lesions and adenocarcinoma of cardia was significantly higher than that in chronic inflammation patients (23.56% and 17.65% vs 2.33%, P<0.05). There was no difference in the percentage of cases with PG I /PG II <6 among the three cardiac lesion patients. In the cases with serum PGI<60N.,g/L, 36.36% were those with precancerous lesions and 54.55% with adenocarcinoma. These two accounted for over 90% of the total. The median levels of PG I,PG II and PG I /PG II ratio in esophagitis cases were all significantly higher than that in esophageal squmaous carcinoma cases, with PG I being the most significant(187.μg/L for esophagitis and 116.00μg/L for carcinoma). It was noted that over 75% of the cases with abnomal PG levels were esophageal carcinoma. Conclusions :PG levels determined with TRFIA could reflect the pathological changes of cardiac mucosa. PG I <60N.,g/L is an important parameter for screening the precancerous lesions and adenocarcinoma of cardia. In addition, serum PG I detection may be a putative parameter in the differential diagnosis of esophagitis and esophageal squmaous carcinoma