The aim of the present study is to analyze dynamic changes in the rating of information sources of medical literature in the sites of the following electronic libraries (<rsl.ru>, <rssi.ru>, <elibrary.ru>) and the rating of information sources for electronic medical books (<booksmed.com>, <medliter.ru> <medbook.net.ru>). While using the on-line programs Alexa and Cy-pr, we have analyzed their website's rating and identified basic data and time-varying site data obtained for fourteen months. Alexa Rank rating was calculated for each sitemonthly. Our study has shown that the most popular information sources of medical education among the six studied sites for Russian users is <elibrary.ru>; the site <rssi.ru> is at the second place.