  Excitation of radial pulsations in red supergiants of Magellanic Clouds is
investigated using the stellar evolution calculations and the self-consistent
solution of the equations of radiation hydrodynamics and turbulent convection.
The stars with initial masses 6M_odot<=M_zams<=28 M_odot and the initial
chemical composition X=0.7, 0.004<=Z<=0.008 are shown to be unstable against
fundamental mode oscillations with periods from 17 to 1200 days as they become
helium burning red supergiants. The period-luminosity relation slightly depends
on the mass loss rate varying with a factor of three, whereas its dependence on
the metal abundance is delta M_bol=0.89 delta log Z. In comparison with
galactic red supergiants (Z=0.02) the low metal abundances in red supergiants
of Magellanic Clouds are responsible for their higher effective temperatures
and substantially narrower ranges of evolutionary stellar radius change during
helium burning. Therefore on the period-mass diagram the red supergiants of
Magellanic Clouds are located within the strip with width of delta log M =
0.09, so that the uncertainty of mass evaluation of the red supergiant with the
known pulsational period is nearly 25%.
