Objective: The aim of this study was to evaluate the plasma changes of cardiac troponin I level (cTnI), homocysteine (Hcy) and the activity of adenosine deaminase (ADA) in the streptozotocin-induced diabetes mellitus and following administration of pure Cynodon dactylon extract in the diabetic rats. Diabetes Mellitus (DM) is known as a metabolic disease which is followed by different blood and tissue complications. Methods: In this research, the cTnI, Hcy and ADA activity was measured in diabetic group after 3-month administration of Cynodon dactylon extract in three 150, 300 and 450 mg/kg doses. Results: The significant increase(P<0.01) in cTnl, Hcy and ADA parameters in diabetic (positive control) group was determined in comparison to the control group (negative control) and a significant decrease of those ones (P<0.01) in the 450 mg/kg dose of Cynodon dactylon in comparison to the diabetic and control group. Conclusion: In conclusion, firstly heart damage occurs in diabetic rats and secondly the Cynodon dactylon extract tremendously influences the reduction of above-mentioned parameters and usage of dried powder and/or extract of Cynodon dactylon rhizomes in the food of the diabetic cases may play important role in the cardiovascular health and increasing the glucose consumption by cells.