Multimorbidity is common in older hospitalized adults. To date, however, few studies have addressed multimorbidity in the older population of Chinese inpatients. We aimed to investigate the multimorbidity rate and associated risk factors in older adult inpatients in China. This study was conducted in the medical wards of a tertiary-care hospital from. The patients were recruited aged between 60 to 101 (74.14±8.46) years. Data were obtained from the China Comprehensive Geriatric Assessment Study, conducted in 2011-2012 in China. A total of 4,633 inpatients older than 60 years was recruited from 12 hospitals in 7 cities throughout China. The prevalence of comorbidity, distribution of common chronic diseases, and the associated risk factors were studied. A total of 4,348 people aged 60 to 101 (74.14±8.46) years completed questionnaires. The average frequency of multimorbidity was 69.3% (95% CI, 67.9% to 70.6%). The prevalence of multimorbidity increased with age and was higher in men (71.6%; 95% CI, 69.9% to 73.3%) than in women (65.3%, 95% CI 63.0% to 67.6%), and higher in the northern region (71.7%, 95% CI 69.9% to 73.5%) than in the southern region (66.0%; 95% CI, 63.8% to 68.1%). The most frequent chronic diseases were hypertension, coronary heart disease, diabetes, cataract, and stroke. Area (OR=0.556; 95% CI, 0.465 to 0.666), region (OR=0.834; 95% CI, 0.723 to 0.962), body mass index (BMI) (OR=1.124; 95% CI, 1.017 to 1.242), and impairment of activities of daily living (OR=0.911; 95% CI, 0.855 to 0.970) were independent factors associated with multimorbidity. Multimorbidity is common in older Chinese inpatients with a national prevalence of 69.3% that increases in line with age. Age, region, area, BMI, and daily activities were independent factors significantly associated with multimorbidity in older inpatients. Clinicians should therefore focus more attention on multimorbidity.