Objective To investigate the types of chronic diseases and distributions and patterns of multimorbidity in the very old inpatients. Methods Clinical data of 1004 elderly hospitalized patients in the Department of Geriatrics of our hospital from June 2013 to June 2016 were collected and retrospectively analyzed. Based on the presence of 23 common chronic conditions, types of these diseases and characteristics of chronic comorbidities were investigated. Student’s t test or one-way analysis of variance was employed for statistical analysis in measure data, and Chi-square test was used for enumeration data.Results Among the 23 obtained chronic diseases, the top 5 common ones were hypertension (72.51%), cerebrovascular disease (52.29%), coronary heart disease (37.25%), cardiac insufficiency (36.25%), and bone and joint disease (33.96%). The rate of multimorbidity (≥2 disease) was 93.73% in the cohort, and the mean number of comorbid conditions was (4.67±2.18). The observed prevalence of paired chronic conditions exceeded the expected prevalence for several paired conditions, such as hypertension and diabetes mellitus(OR=1.25, 95%CI 1.02-1.54; P=0.03), coronary heart disease and cardiac insufficiency(OR=2.14, 95%CI 1.69-2.69; P<0.01), and cardiac insufficiency and arrhythmia(OR=1.77, 95%CI 1.34-2.35; P<0.01). Conclusion The very old individuals show characteristics of higher prevalence of multimorbidity and greater number of chronic diseases or conditions. These conditions may be associated with each other and form special paired chronic conditions.