Previous studies have indicated that exposure of fibrinogen receptors associated with the glycoprotein IIb/IIIa complex contributes to platelet loss during cardiopulmonary bypass. TAK-029 is a newly developed reversible, nonpeptide inhibitor of platelet glycoprotein IIb/IIIa receptors. In this study, we tested the platelet preserving effect of TAK-029 in an in vitro model. The methods included the comparison of the release ofβ-thromboglobulin (β-TG) between a TAK-029 group (n = 5) and a control group (n = 5) in a mock circulation under a shear force generated by a centrifugal pump. To evaluate the degree of β-TG release,Δβ-TG/ΔT was calculated whereΔβ-TG is the increase in β-TG andΔT is the time. The results showed that the value ofΔβ-TG/ΔT in the TAK-029 group was significantly lower than it was in the control group (4.22 ± 0.27× 102 ng/ml, respectively). In conclusion, TAK-029 reduced the platelet activation under the shear forces of an in vitro model, suggesting that TAK-029 is a potential candidate for platelet protection during cardiopulmonary bypass.