Dynamic spiral domains were found to exist in Gd-Co amorphous films in narrow temperature ranges near (below and above) the magnetization compensation point. The diagrams of the formation of dynamic spiral domains were plotted on the frequency-amplitude of ac magnetic field coordinates for the temperatures corresponding to the middle of the temperature range of their existence. The similarity of and difference in the dynamic domain structures of iron garnet and amorphous films were studied. The necessary conditions for the formation of spiral domains, in particular, the absence of flexural instability of spiral domain upon magnetization reversal were discussed.