  We discuss on the basis of our evolutionary spectral models the impact of
chemical composition on the spectrum of stellar population formed in the
starburst. Their metallicity range Z=0.0001 - 0.05(0.1) fully covers the
observable one; depending on age, wavelength region and IMF the UV-fluxes
differ between extreme compositions at least tenfold, usually more.
Independently of age, UV-fluxes shortwards of Balmer jump monotonically decline
with the growth of metallicity. Optical and especially IR-region are also
influenced, with the typical difference 10-50 times in fluxes at wavelengths >1
micron. In IR the situation which composition is the brightest emitter gets
reversed with age.
