The velocity and concentration fields of two-phase vortex flows have been studied. Analytical methods were used where possible to solve a number of particularly simple cases easy to be interpreted physically. Two cases of gaseous motion were considered : the vortex with concentrated vorticity and the Rankine vortex. For each vortex, the motion of one particle was studied at first, using an asymptotic multiple scales method, and the results were compared with numerical data. Then an equivalent particle continuum was analyzed, first in terms of Lagrangian coordinates, then in Eulerian variables, assuming the time dependent or stationary solutions to be rotationally invariant.