A fluid pressure circuit comprising: an HST circuit including a variable capacity fluid pressure pump to be driven by a mechanism to perform forward-reverse rotation, a fluid pressure motor to be driven by fluid discharged from the fluid pressure pump to perform forward-reverse rotation, a first line configured to connect a first port of the fluid pressure pump and a first port of the fluid pressure motor, and a second line configured to connect a second port of the fluid pressure pump and a second port of the fluid pressure motor; an accumulator connected in parallel with the fluid pressure pump; an accumulator pump configured to accumulate pressure fluid in the accumulator; and an accumulator switching valve (14, 20, 25) configured to switch connection between the fluid pressure motor and the accumulator, characterized in that the accumulator switching valve has a first position (14-A, 20-A, 25-A) at which the accumulator is connected to the first port of the fluid pressure motor and the second port of the fluid pressure motor is connected to a reservoir tank, a second position (14-B, 20-B, 25-B) at which the accumulator is connected to the second port of the fluid pressure motor and the first port of the fluid pressure motor is connected to the reservoir tank, and a third position (14-N, 20-N, 25-N) at which the accumulator and the reservoir tank are in non-connection with the first line and the second line. an HST circuit including a variable capacity fluid pressure pump to be driven by a mechanism to perform forward-reverse rotation, a fluid pressure motor to be driven by fluid discharged from the fluid pressure pump to perform forward-reverse rotation, a first line configured to connect a first port of the fluid pressure pump and a first port of the fluid pressure motor, and a second line configured to connect a second port of the fluid pressure pump and a second port of the fluid pressure motor; a variable capacity fluid pressure pump to be driven by a mechanism to perform forward-reverse rotation, a fluid pressure motor to be driven by fluid discharged from the fluid pressure pump to perform forward-reverse rotation, a first line configured to connect a first port of the fluid pressure pump and a first port of the fluid pressure motor, and a second line configured to connect a second port of the fluid pressure pump and a second port of the fluid pressure motor; an accumulator connected in parallel with the fluid pressure pump; an accumulator pump configured to accumulate pressure fluid in the accumulator; and an accumulator switching valve (14, 20, 25) configured to switch connection between the fluid pressure motor and the accumulator, characterized in that the accumulator switching valve has a first position (14-A, 20-A, 25-A) at which the accumulator is connected to the first port of the fluid pressure motor and the second port of the fluid pressure motor is connected to a reservoir tank, a second position (14-B, 20-B, 25-B) at which the accumulator is connected to the second port of the fluid pressure motor and the first port of the fluid pressure motor is connected to the reservoir tank, and a third position (14-N, 20-N, 25-N) at which the accumulator and the reservoir tank are in non-connection with the first line and the second line. a first position (14-A, 20-A, 25-A) at which the accumulator is connected to the first port of the fluid pressure motor and the second port of the fluid pressure motor is connected to a reservoir tank, a second position (14-B, 20-B, 25-B) at which the accumulator is connected to the second port of the fluid pressure motor and the first port of the fluid pressure motor is connected to the reservoir tank, and a third position (14-N, 20-N, 25-N) at which the accumulator and the reservoir tank are in non-connection with the first line and the second line.