Provided are a blood-collecting bag allowing the removal of initial flow blood by which initial flow blood can be collected, the blood to be examined can be easily collected and the blood can be easily transported by capillary action and a blood-collecting set allowing the removal of initial flow blood. A blood-collecting bag (B) allowing the removal of initial flow blood and wherein first to third partition parts (P1, P2 and P3) and an air-guiding part (R) are formed so as to definitely divide the inside of a bag main body (21) as roughly linear partitions and thus an almost circulatory continuous pattern starting from the direction of a blood inlet (23), passing the (right) side part direction and bottom part direction and (left) side part direction of the bag main body (21) and then returning to the direction of the blood inlet (23) again is formed.
