The live shows, from content partners Howcast, Next New Networks, Rocketboom and Young Hollywood, follow on from YouTube's broadcasts of live matches from the Indian Premier League and concerts from the rock band U2 on You Tube.
The live programming started at 8am Pacific Time and shows on during the first day included Rocketboom live and Tony Hawk Kicks Back at the YH Studio.
According to YouTube the new platform integrates live streaming directly into YouTube channels and all broadcasters need is a webcam or external camera.
The live stream includes a 'Live Comments' module which allows users to engage with the broadcaster and community.
On a YouTube blog post it asked users to "bear with us as we test this new platform as there may be some bumps along the way" and asked users to share feedback in the comments section.
Brylcreem and Lebara Mobile became the first brands to sponsor a live sports event on YouTube when they signed up to the video site's coverage of the Indian Premier League cricket in March.