Fluid pump, in particular a liquid pump having a rotor (18) with at least one rotor blade (20, 21) for conveying the fluid, the rotor being variable with respect to its diameter between a first, compressed state and a second expanded state. In order to produce simple compressibility and expandibility of the rotor of the pump, it is provided according to the invention that at least one rotor blade is deformable between a first state which it assumes in the compressed state of the rotor and a second state which it assumes in the expanded state of the rotor by means of a fluid counterpressure (23) during a rotation of the rotor during pump operation. The deformation of the blade is facilitated by providing a leading (27) and a trailing side (28) of the blade in the direction of movement during the conveying operation, wherein said sides have different configurations in the form of different material properties and/or constructional assembley at least along a part of the distance between the radially outer tip of the blade and the radially inner end of the blade.
