Method and apparatus for measuring an audience viewership of an online live broadcast are provided. Code information included in live broadcast data is received from the encoding server or the media server, transmission information of the live broadcast data to the client is received from the media server, the transmission information is compensated using the code information, and the audience viewership of the online live broadcast is computed using the compensated transmission information. It is possible to obtain the accurate viewership of an online live broadcast and to obtain the accurate viewership of the online live broadcast even when users erroneously access a web page or intentionally access the web page to increase the number of page views.