【Objective】 To explore the clinical value of thromboelastogram (TEG) in monitoring coagulation function in patients with COVID-19. 【Methods】 Patients diagnosed with COVID-19 in our hospital from January 20 to March 1, 2020 were enrolled and divided into mild group (mild type, common type) and severe group (severe type, critical group). The TEG, platelet count and routine blood coagulation function were compared between the two groups to analyze the coagulation characteristics of the patients. 【Results】 A total of 66 cases were studied, including severe (n=33) and mild (n=33), male(n=39)and female(n=27), hypertension (n=9) and diabetes mellitus (n=11) cases. 28 (84.8%) severe and 24 (72.7%) mild patients had at least one hypercoagulable TEG parameter. K value of TEG in the severe group was lower than that in the mild group (P<0.05), Angel and CI increased (P<0.05). The fibrinogen (Fib) and D-dimer increased in routine coagulation function test (P<0.05). 【Conclusion】 Patients with COVID-19 showed hypercoagulability in TEG parameter, which was related to the severity of this disease. TEG may be more valuable for COVID-19 patients with hypercoagulable status and thrombosis risk, and help to develop anticoagulation strategies.