ABSTRACT
The orbital period and the light-curve variations of the binary system RS CVn are rediscussed according to a long series of photometric observations made at Catania Observatory since 1963. The period of the migrating wave-like distortion on the light-curve outside eclipses and its role in determining the photometric variations during eclipses are examined. The results obtained make quite improbable Hall's explanations of the erratic changes of the orbital period. Key words: binary systems - orbital period - light-curve variations