Objective To analyze the clinical characteristics of the elderly patients with influenza A (H1N1), compare their findings in routine blood tests, serum albumin and inflammatory factors with the findings of patients catching cold, and determine their significance for clinical guidance. Methods A total of 70 patients (35 H1N1 patients; 35 non-H1N1 patients as control group) were recruited in Department of Geriatrics of Xijing Hospital from December 2018 to March 2019. Findings in routine blood tests and serum albumin levels were compared between the two groups. A comparison was also made in the H1N1 group of the above indicators, interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP) and serum amyloid A (SAA) before and after the treatment. SPSS statistics 24.0 was used for data analysis. t test was perfomed for data comparison between two groups. Results Of 35 patients with H1N1,32(91.4%) were cured, and 3(8.6%) died of severe H1N1 with pneumonia. Compared with the control group, white blood cell count (P<0.05) and absolute value of neutrophils and percentage (P<0.01) were much higher in the H1N1 group, and the difference was statistically significant, but absolute value of lymphocytes and the percentage (P<0.01) and serum albumin levels (P<0.05) were significantly lower. In the H1N1 patients clinically cured, absolute value of lymphocytes and the percentage increased significantly after treatment (P<0.01), and the levels of IL-6, hs-CRP and SAA decreased significantly (P<0.01). The difference was statistically significant. Conclusion Lymphocyte count and the percentage are significantly reduced in the elderly patients with H1N1. Lymphocytes and the percentage, IL-6, hs-CRP, and SAA can be used as indicators for therapeutic efficacy. On the treatment of H1N1, the nutritional status of the elderly patients should also be concerned.