PROBLEM TO BE SOLVED: To provide a catheter assembly for accelerating the flow of blood in a proximal direction. A catheter assembly (10) includes a catheter (12), an inner needle (14) having a flow path (15) inserted into the catheter (12) and capable of flowing blood in a proximal direction at the time of puncturing a living body, and a base of the inner needle (14). A needle hub 16 for holding the end side is provided. The needle hub 16 includes a visible portion 45 that allows the user to visually recognize the blood flowing through the flow path 15, and a negative pressure applying mechanism portion 46 that applies negative pressure to the flow path 15. As a result, the catheter assembly 10 can speed up the flow of blood in the flow path 15 to which the negative pressure is applied, promote the shortening of the treatment time, and make the treatment more safe. [Selection diagram] Fig. 2【課題】基端方向への血液の流動を迅速化するカテーテル組立体を提供する。【解決手段】カテーテル組立体１０は、カテーテル１２と、カテーテル１２内に挿入され、生体への穿刺時に血液を基端方向に流動可能な流路１５を有する内針１４と、内針１４の基端側を保持する針ハブ１６とを備える。針ハブ１６は、流路１５を流動した血液をユーザに視認させる被視認部４５と、流路１５に陰圧を付与する陰圧付与機構部４６とを備える。これによりカテーテル組立体１０は、陰圧を付与した流路１５において血液の流動が迅速化し、処置の短時間化を促すと共に、処置を一層安全に実施させることができる。【選択図】図２
