Disclosed is a work vehicle having hydraulic transmission device. The hydraulic transmission device prevents the port of valve from erosion by the operating oil emitted from the slot of the valve toward the port inside the valve. The work vehicle has a hydraulic transmission device comprising: an input shaft, operated by receiving the driving power from the driving source； a cylinder block at the input side rotating with the input shaft； a cylinder block at the output side rotating via the fluid pressure from the cylinder block at the input side； and an input shaft rotating with the cylinder block at the output side. The cylinder block at the input side or the cylinder block at the output side respectively comprise a plurality of cylinders and valves (86) comprising the port for the working oil from the cylinders are provided. The port has a plurality of slots (84), wherein the extension lines of the plurality of slots (84) are crossed with each other within the port.本發明提供一種具備液壓式變速裝置的作業車輛，該液壓式變速裝置可避免閥板的開口被從閥板的槽朝向閥板內的開口噴出的作動油浸蝕。該作業車輛設置有液壓式變速裝置，該液壓式變速裝置係具備：輸入軸，接受來自驅動源的驅動力而作動；輸入側的汽缸體，與該輸入軸一體旋轉；輸出側的汽缸體，利用來自該輸入側的汽缸體的液壓而旋轉；以及輸出軸，與該輸出側的汽缸體一體旋轉；在前述輸入側的汽缸體或前述輸出側的汽缸體分別具備複數個汽缸，並設置具備來自前述汽缸的作動油的開口的閥板(86)，在前述開口設置有複數個槽(84)，複數個槽(84)的延長線彼此在開口內交叉。
