To provide a thermoelectric power generation system capable of recovering power efficiently even when the generating power (generating voltage) of a thermoelectric conversion element is varied.

The thermoelectric power generation system 1 comprises thermoelectric conversion modules 3, 4 and 5 connected with a step-down converter 8 and a step-up converter 9 through a switch matrix 6 and a change-over switch 7. The switch matrix 6 comprises a plurality of switches and can regulate the arrangement of the thermoelectric conversion modules 3, 4 and 5 in parallel or series. A controller 10 regulates the arrangement of the thermoelectric conversion modules 3, 4 and 5 based on the open voltage thereof.