The present invention provides a blood collection container capable of allowing blood to coagulate in a short time and preventing blood from coagulating with bubbles contained therein and thus preventing formation of bubbly clots when used to collect blood therein. A blood collection container 1 stores a blood coagulation promoting agent 4 for promoting blood coagulation and an antifoaming agent 5, which is a polyoxyalkylene or a derivative thereof. The amount of the antifoaming agent 5 is 2.0 × 10-3 to 0.2 mg per mL of blood to be collected in the blood collection container 1.