A loader work machine is disclosed in which a base portion of each of right/left arms (77) is received by an arm support portion (164) of a first lift link (81) and pivotally supported by a first arm shaft (88), and a hydraulic pipe arrangement (167) connected to a hydraulic actuator (98) extend through an support frame (11) from inside to outside of its inner wall (12), and toward an arm (77). The base portion of the arm (77) is supported to the arm support portion (164) at a position adjacent a link outer wall (157) in a transverse direction so that a hose accommodation space (165) is formed between a link inner wall (156) and an internal side face of the base portion of the arm (77). The hydraulic pipe arrangement (167) runs frontward of the first arm shaft (88) and a first link shaft (85), and is disposed in the hose accommodation space (165).