Coronary heart disease is one of the deadliest cardiovascular disease in the world. Recent studies have shown an increase in aspirin resistance as a gold standard therapy causing recurrent heart attacks. Antiplatelet of natural resources thus need to be explored. Garlic (Allium sativum) is known to be effective as an antiplatelet, but the problem arose after consuming garlic prolonged is the presence of unpleasant breath and body odor which reduces patient compliance in therapy. Black Garlic is a product made of garlic which tastes delicious and does not smell pungent like raw garlic. There has been no study of Black Garlic as an antiplatelet before. The aim of this research was to determine the antiplatelet activities of aqueous extract of garlic (AEG) and Black Garlic (AEBG) and to evaluate their differences in human blood in vitro. This research was designed to be experimental posttest only, which was performed in 10 groups, namely the vehicle controls, positive controls, as well as the concentration groups of AEG and AEBG (each 1-4μg/μL). The antiplatelet activity was tested using the Born method, which measured the plasma uptake before and after induced with Papain. Evaluation was done by calculating the percent inhibition of platelet aggregation of the concentration groups relative to vehicle controls. The results showed that both AEG and AEBG have antiplatelet activities ([H=16.664; 5 df; p=0.005] and [H=16.225; 5 df; p=0.006] respectively). The inhibition of platelet aggregation is also shown to be significantly different in both samples [H=21.693; 7 d.f; p=0.003].