A pandemic caused by SARS-CoV-2 has infected more than 2 million people and killed exceeding 150,000 people around the world as of April 19,2020. We obtained the clinical data of all diagnosed patients in Fuyang, Anhui province to investigate indicators that can be used to assess severity of COVID-19. Of the 155 patients, 87(56.13%) were males. The mean age was 41.95 (SD 15.34) years. Only 30(19.35%) patients had critical condition. Fever (84.52%) followed by cough (81.94%) were the most common symptoms, and short of breath was more common in severe patients (P<0.01). Lymphopenia was observed in most patients (74, 47.7%). It showed the elevation of C-reaction protein (CRP) in 100 (64.5%) patients and the elevation of serum amyloid protein A (SAA) in 104 (67.1%) patients. Interleukin 6 (IL-6) was above the normal range in 104 (67.1%) patients. The calculated cut-off value of CRP was 19.35 mg/mL, the AUC was 0.777, sensitivity was 73.3%, specificity was 69.6%; SAA was 73.55 mg/L, 0.679, 83.3%, 56.8% respectively; IL-6 was 18.85 pg/mL, 0.797, 83.3%, 64.8%; D-Dimer was 0.325 mg/L, 0.673, 66.7% and 68.8%. The combination of CRP, SAA, IL-6 and D-Dimer was 0.823 in AUC, 73.3% in sensitivity and 78.4% in specificity. Old age, co-existing disease and lymphopenia are related to severe COVID-19. Elevated CRP, SAA, IL-6 and D-Dimer can be predictors to severe COVID-19. The combination of these four indicators can improve the effectivity and specificity of assessing severe COVID-19.