Objective:To explore the correlation between the irradiation volume and time and the absolute value of peripheral blood lymphocytes in patients with esophageal cancer. Methods: From January 2019 to December 2019, in the First Affiliated Hospital of Bengbu Medical College, 84 patients with esophageal cancer treated by radiotherapy or combined chemotherapy including 24 patients with radiotherapy alone and 60 patients with radiotherapy combined chemotherapy, were included in the study protocol. The peripheral blood leukocyte (WBC), neutrophil (n), lymphocyte (L), hemoglobin (HB) and platelet (PLT) counts of the patients were measured by blood cell analyzer. Pearson correlation was used to analyze the relationship between irradiation time, dose and volume and peripheral blood parameters. Results: In patients with radiotherapy for esophageal cancer, including the subgroup of concurrent radiotherapy and chemotherapy and radiotherapy alone, there was no correlation between radiation duration and peripheral blood indexes during 1-6 weeks of treatment (P>0.05). However, at the 5-6 weeks of radiotherapy, the radiotherapy dose of patients was negatively correlated with WBC, N, L and HB (P<0.05), while the radiation dose of patients in the concurrent radiotherapy and chemotherapy subgroup was negatively correlated with WBC, N, L and HB (P<0.05). At 1-4 weeks of treatment, there was no correlation between the corresponding irradiation volume of different gradient irradiation doses and peripheral blood indexes (P>0.05). However, at the 5th to 6th week, the exposure volume of patients under different gradient exposure doses was negatively correlated with WBC and N (P<0.05), while the exposure volume under 20Gy-60Gy exposure doses, especially 20Gy and 30Gy exposure doses, was negatively correlated with L (P<0.05). In the concurrent chemoradiotherapy subgroup, the exposure volume was negatively correlated with WBC and N at different exposure doses (P<0.05), while the exposure volume was negatively correlated with L at 20Gy-60Gy exposure dose (P<0.05), and the exposure volume was negatively correlated with HB at 60Gy exposure dose (P<0.05). Conclusion: Radiation volume and dose were negatively correlated with peripheral blood lymphocyte count of patients with esophageal cancer, baseline lymphocytes were positively correlated with peripheral blood lymphocyte count of patients with esophageal cancer, while exposure time was not correlated with peripheral blood lymphocyte count of patients with esophageal cancer. [ABSTRACT FROM AUTHOR]