Abstract: Objective To investigate the effect of ticagrelor plus aspirin on fibrinogen (Fib) and high sensitivity C-reactive protein (hs-CRP) in elderly patients with acute coronary syndrome (ACS) and diabetes mellitus (DM), and evaluate its safety for these patients. Methods One hundred and ten patients (aged from 60 to 80 years) with ACS and DM in the First Affiliated Hospital of Jiamusi University from November 2015 to February 2017 were enrolled in our study, and they were randomly divided into control group (n=55) and treatment group (n=55). Patients in control group were orally administrated clopidogrel at a loading dose of 300 mg, with maintenance dose of 75 mg once daily. The patients in treatment group were orally administered ticagrelor at a loading dose of 180 mg, with maintenance dose of 90 mg twice daily. Patients in the two groups received aspirin 100 mg once daily. The effect of ticagrelor versus clopidogrel on Fib and hs-CRP were compared at 3, 7 and 30 days after treatment, and their drug safety were evaluated. Results At 3 days after treatment, the levels of Fib and hs-CRP showed no significant difference between the two groups (P > 0.05); At 7 days after treatment, Fib and hs-CRP in treatment group were significantly lower than those in control group(3.15±0.45)g/L vs (3.39±0.52)g/L, (8.20±3.71)mg/L vs (10.36±5.26)mg/L, both P < 0.05. After treatment for 30 days, the levels of Fib and hs-CRP in treatment group decreased significantly compared with control group(2.19±0.24) g/L vs (2.87±0.31)g/L, (3.14±1.08) mg/L vs (4.25±1.37)mg/L, both P < 0.01. Levels of Fib and hs-CRP in two groups decreased significantly when compared with the baseline (All P < 0.01), and the incidences of the major adverse cardiovascular events (MACEs) in treatment group were lower than those of control group (All P < 0.05), but no significant difference was found in bleeding between the two groups (P > 0.05). Conclusion Compared with clopidogrel, ticagrelor can effectively reduce the levels of Fib and hs-CRP in elderly patients with ACS and DM, and its effect on thromboembolism and anti-inflammatory is superior, which is safe for patients in clinical treatment.