A radial piston fluid machine comprising: a rotation shaft; a housing comprising at least one cylinder part extending along a radial direction of the rotation shaft; a piston arranged in the cylinder part and forming a working chamber with the at least one cylinder part; a converting mechanism (32, 34, 36) for performing conversion between rotational motion of the rotation shaft and reciprocating motion of the piston; and a valve block which is fixed to the housing and to which at least one high pressure valve and at least one low pressure valve are attached, said at least one high pressure valve being provided to regulate flow of high pressure working fluid, said at least one low pressure valve being provided to regulate flow of low pressure working fluid, wherein the valve block includes: a valve-block high pressure port; a valve-block high pressure passage which extends in the valve block to connect the valve-block high pressure port and the working chamber via the high pressure valve; a valve-block low pressure port; and a valve-block low pressure passage which extends in the valve block to connect the valve-block low pressure port and the working chamber via the low pressure valve, and wherein the housing includes: a housing high pressure port connected to the valve-block high pressure port; a housing high pressure passage which extends in the housing from the housing high pressure port; a housing low pressure port which is connected to the valve-block low pressure port; and a housing low pressure passage which extends in the housing from the housing low pressure port, said radial piston fluid machine being characterized in that said at least one cylinder part includes a plurality of the cylinder parts arranged along the axial direction of said rotation shaft, and said housing high pressure passage includes a high-pressure axial passage which extends in the housing along the axial direction of the rotation shaft and is connected to the plurality of the cylinder parts. a rotation shaft; a housing comprising at least one cylinder part extending along a radial direction of the rotation shaft; a piston arranged in the cylinder part and forming a working chamber with the at least one cylinder part; a converting mechanism (32, 34, 36) for performing conversion between rotational motion of the rotation shaft and reciprocating motion of the piston; and a valve block which is fixed to the housing and to which at least one high pressure valve and at least one low pressure valve are attached, said at least one high pressure valve being provided to regulate flow of high pressure working fluid, said at least one low pressure valve being provided to regulate flow of low pressure working fluid, wherein the valve block includes: a valve-block high pressure port; a valve-block high pressure passage which extends in the valve block to connect the valve-block high pressure port and the working chamber via the high pressure valve; a valve-block low pressure port; and a valve-block low pressure passage which extends in the valve block to connect the valve-block low pressure port and the working chamber via the low pressure valve, and a valve-block high pressure port; a valve-block high pressure passage which extends in the valve block to connect the valve-block high pressure port and the working chamber via the high pressure valve; a valve-block low pressure port; and a valve-block low pressure passage which extends in the valve block to connect the valve-block low pressure port and the working chamber via the low pressure valve, and wherein the housing includes: a housing high pressure port connected to the valve-block high pressure port; a housing high pressure passage which extends in the housing from the housing high pressure port; a housing low pressure port which is connected to the valve-block low pressure port; and a housing low pressure passage which extends in the housing from the housing low pressure port, said radial piston fluid machine being characterized in that said at least one cylinder part includes a plurality of the cylinder parts arranged along the axial direction of said rotation shaft, and said housing high pressure passage includes a high-pressure axial passage which extends in the housing along the axial direction of the rotation shaft and is connected to the plurality of the cylinder parts. a housing high pressure port connected to the valve-block high pressure port; a housing high pressure passage which extends in the housing from the housing high pressure port; a housing low pressure port which is connected to the valve-block low pressure port; and a housing low pressure passage which extends in the housing from the housing low pressure port, said radial piston fluid machine being characterized in that said at least one cylinder part includes a plurality of the cylinder parts arranged along the axial direction of said rotation shaft, and said housing high pressure passage includes a high-pressure axial passage which extends in the housing along the axial direction of the rotation shaft and is connected to the plurality of the cylinder parts.