  We investigate the sample of 213 GPS sources selected from simultaneous
multi-frequency 1-22 GHz observations obtained with RATAN-600 radio telescope.
We use publicly available data to characterize parsec-scale structure of the
selected sources. Among them we found 121 core dominated sources, 76 Compact
Symmetric Object (CSO) candidates (24 of them are highly probable), 16 sources
have complex parsec-scale morphology. Most of GPS galaxies are characterized by
CSO-type morphology and lower observed peak frequency (~1.8 GHz). Most of GPS
quasars are characterized by "core-jet"-type morphology and higher observed
peak frequency (~3.6 GHz). This is in good agreement with previous results.
However, we found a number of sources for which the general relation CSO -
galaxy, core-jet - quasar does not hold. These sources deserve detailed
investigation. Assuming simple synchrotron model of a homogeneous cloud we
estimate characteristic magnetic field in parsec-scale components of GPS
sources to be B ~ 10 mG.
