A kind of blood collecting pen structure, including a penholder and a cap. Penholder includes a bundle blood needle, and cap then releasably assembles what penholder and bundle blood needle is enable movably to pierce out. Cap includes an ontology, a cap head and an identification piece. Ontology is provided with a form. Cap head socket and can opposing body rotation, and have an at least drive portion. Identification piece assembling what cap head is interior and follows the rotation of cap head and opposing body's rotation, the mark part that there is identification piece the plural number of corresponding drive portion to be driven portion and setting corresponding with form. It thereby assembles cap head and identification piece to facilitate, be hardly damaged, and cost reduces.一種採血筆結構，包括一筆桿及一帽蓋。筆桿包含一扎血針，帽蓋則拆卸地組裝於筆桿並使扎血針能夠移動地刺出。帽蓋包含一本體、一帽頭及一標識件。本體設置有一視窗。帽頭套接且能夠相對本體旋轉，且具有至少一帶動部。標識件組裝於帽頭內並跟隨帽頭的旋轉而相對本體轉動，標識件具有相對應帶動部的複數被帶動部及與視窗相對應設置的一標識部。藉此使帽頭與標識件組裝便利，不易損壞，且成本降低。
