2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/113282We present a preliminary statistical analysis of a period change of eclipsing binaries from the ASAS Catalog of Variable Stars. For each contact and semidetached system brighter than 13.3$mag$ (in V) with a period shorter than 0.4 days and at least 300 observation points we have found an angular velocity $ω$ and its time derivative $\frac{dω}{dt}$. According to our accuracy there is no evidence that average $\frac{dω}{dt}$ differs from 0. Light curves for selected stars are presented.Published in Proceedings of the 13th Young Scientists' Conference on Astronomy and Space Physics, held in Kyiv, Ukraine, April 25-29, 2006, Eds.: Golovin, A.; Ivashchenko, G.; Simon, AAstrophysicstext