Provided is a blood collection container that can coagulate blood in a short amount of time and can inhibit blood coagulation in a state of containing air bubbles and generation of bubbly blood clots when blood is collected into the blood collection container. A blood collection container (1) houses a blood coagulation promoter (4) that promotes blood coagulation and a defoamer (5) that is a polyoxyalkylene or derivative thereof. The volume of the defoamer (5) is in the range of 2.0 x 10-3 - 0.2 mg per 1 mL of blood collected into the blood collecting container (1).