To provide a flow dividing system that has an improved degree of freedom in arrangement, is suitable for integration, and achieves reductions in the manufacturing costs and maintenance costs. A flow dividing system for controlling, upon dividing a single flow rate into multiple flow rates, the respective flow rates such that the ratio between the divided flow rates matches a preset flow rate ratio. The flow dividing system has: a manifold 500 for dividing the single flow rate into the multiple flow rates; and multiple fluid control devices 1M, 1S that are formed as separate bodies from the manifold 500, are disposed separately from and independently of each other, and respectively control the multiple flow rates. A master device 1M has communication unit 102M for transmitting a preset flow rate value based on the preset flow rate ratio to a slave device 1S and for receiving a flow rate detection value DQ2 from the slave device 1S, and the slave device 1S has a communication unit 102S for receiving the preset flow rate value from the master device 1M and for transmitting the flow rate detection value DQ2 to the master device 1M.