A uniflow scavenging two-cycle engine includes a scavenge port which is provided on one end side in a stroke direction of a piston in a cylinder (110), and sucks an active gas; and a plurality of injection units (126g and 126f) which inject a fuel gas into the active gas sucked into the scavenge port and are provided on an inner circumferential surface of the scavenge port or on the outside of the cylinder compared to the inner circumferential surface, and have different positions of the piston in the stroke direction. Further, the plurality of injection units are divided into at least two sets of injection unit groups include a first injection unit group (160) and a second injection unit group (162), the first injection unit group being a set of one or a plurality of injection units located on the other end side in the stroke direction, and the second injection unit group being a set of one or a plurality of injection units located on one end side in the stroke direction, and the injection stop of the fuel gas is later in the injection unit of the first injection unit group than in the injection unit of the second injection unit group. With the configuration, it is possible to provide a scavenging two-cycle engine which suppresses blow-by of the fuel gas, while uniformly diffusing the fuel gas.