This creation is a kind of syringe (one), comprising: a syringe, an adapter and a push rod. The stepped structure system of the interior forward end of syringe has a taper annular groove, a clip annular groove and a bump, and taper annular groove and the presentation of clip annular groove are ladder-like, and bump is swelled by taper annular groove lower edge. Adapter installs what syringe interior forward end, and the ring tapering of adapter is accordingly sticked what taper annular groove, and the blocking part correspondence of adapter sets what clip annular groove, and the bottom end of adapter is by bump institute clip. Inside push rod accommodating what syringe and push rod front end is mobile and supports what adapter bottom end, and push rod front end is connected with adapter bottom end； The taper annular groove of syringe is in ramp-like, and ring tapering is in corresponding ramp-like skewed, so that ring tapering consolidation is sticked what taper annular groove, it is ensured that adapter is fitted close with syringe.本創作係一種注射器(一)，包括：一針筒、一轉接頭及一推桿。針筒的內部前端的階狀結構係具有一錐形環槽、一卡掣環槽及一隆起塊，錐形環槽與卡掣環槽呈現階梯狀，隆起塊由錐形環槽下緣所隆起。轉接頭裝設於針筒內部前端，轉接頭的環錐部對應地貼設於錐形環槽，轉接頭的卡掣部對應設於卡掣環槽，轉接頭的底端受隆起塊所卡掣。推桿容置於針筒內部且推桿前端移動且抵頂於轉接頭底端，推桿前端與轉接頭底端相連結；針筒之錐形環槽呈斜狀，環錐部呈對應斜狀的傾斜狀，以便於環錐部緊實貼設於錐形環槽，確保轉接頭與針筒作緊密配合。
