To provide a bearing holding device for a radial type variable displacement fluid machine capable of constantly holding an eccentric cam ring and a cage member at optimum positions.

In this bearing holding device, the eccentric cam ring 2 is slidably supported by thrust bearing surfaces 13a and 13b and flat surfaces 12a and 12b formed at the outer circumferential wall of the eccentric cam ring 2 in a casing 1, and a plate 18 is supported so as to be rotatable around a pin 17 in a flat cage 15 disposed between the thrust bearing surface 13a and the flat surface 12. Slits 18a and 18b formed at both ends of the plate 18 are engaged with a pin 19 provided on a side end surface 30a of the eccentric cam ring 2 and a pin 20 provided on a side end surface 31a of the casing with a clearance.