Clinical and laboratory data on patients with coronavirus disease 2019 (COVID-19) in Beijing, China, remain extremely limited. In this study, we summarized the clinical characteristics of patients with COVID-19 from a designated hospital in Beijing. In total, 55 patients with laboratory-confirmed SARS-CoV-2 infection in Beijing 302 Hospital were enrolled in this study. Demographic data, symptoms, comorbidities, laboratory values, treatments, and clinical outcomes were all collected and retrospectively analyzed. A total of 15 (27.3%) patients had severe symptoms, the mean age was 44.0 years (interquartile range [IQR], 34.0-56.0), and the median incubation period was 7.5 days (IQR, 5.0-11.8). A total of 26 (47.3%) patients had exposure history in Wuhan of less than 2 weeks, whereas 20 (36.4%) patients were associated with familial clusters. Also, eighteen (32.7%) patients had underlying comorbidities including hypertension. The most common symptom of illness was fever (45; 81.8%); 51 (92.7%) patients had abnormal findings on chest computed tomography. Laboratory findings showed that neutrophil count, percentage of lymphocyte, percentage of eosinophil, eosinophil count, erythrocyte sedimentation rate, albumin, and serum ferritin are potential risk factors for patients with a poor prognosis. A total of 26 patients (47.3%) were still hospitalized, whereas 29 (52.7%) patients had been discharged. Compared with patients in Wuhan, China, the symptoms of patients in Beijing are relatively mild. Older age, more comorbidities, and more abnormal prominent laboratory markers were associated with a severe condition. On the basis of antiviral drugs, it is observed that antibiotics treatment, appropriate dosage of corticosteroid, and gamma globulin therapy significantly improve patients' outcomes. Early identification and timely medical treatment are important to reduce the severity of patients with COVID-19.