Hydraulic system for working machine

A hydraulic system for a working machine, comprising:

• a hydraulic pump to output an operation fluid;
• a first hydraulic actuator;
• a second hydraulic actuator;
• a first control valve to control the first hydraulic actuator, the first control valve having an output port;
• a second control valve to control the second hydraulic actuator, the second control valve being arranged on a downstream side of the first control valve;
• a return fluid tube in which a return fluid discharged from the first hydraulic actuator flows, the return fluid tube connecting the first control valve and the first hydraulic actuator;
• a first inner fluid tube provided in the first control valve and connected to the return fluid tube;
• an outer fluid tube connected to the first inner fluid tube through the output port, the outer fluid tube connecting and extending between the output port of the first control valve and the second control valve;
• a return-discharge fluid tube provided outside the first control valve to discharge the return fluid, the return-discharge fluid tube being branched from the outer fluid tube;
• and
• a throttle provided in the return-discharge fluid tube.