New channels will have to get 10,000 views before they can be considered for the YouTube Partner Program, the firm announced in a blog post.
YouTube will then evaluate whether the channel is adhering to its guidelines before letting it carry adverts.
It will help clamp down on content theft and fake channels, YouTube said.
"After a creator hits 10k lifetime views on their channel, we'll review their activity against our policies," wrote Ariel Bardin, vice president of product management at YouTube.
"If everything looks good, we'll bring this channel into YPP [YouTube Partner Program] and begin serving ads against their content. Together these new thresholds will help ensure revenue only flows to creators who are playing by the rules."
Qingzhen Chen, senior analyst for advertising research from IHS, said it would not be difficult for most channel creators to get 10,000 views from a global audience of more than one billion users.
"That's views not subscriptions - so even when people don't watch the whole video that's still considered a view," she said.
"We need to think about why YouTube is doing this. There are have been troubles recently in the news about some of its content, some big brands and agencies have pulled their adverts - this is just another effort to deal with the those issues.
"Publishers are increasingly going to spend their money on digital so they are going to be asking for more in terms of their ads appearing alongside the right content."
YouTube does not publish the figures video creators can earn from pre-roll adverts, which play before their video begins, but in 2014 the New York Times quoted an ad software firm which suggested the average rate was $7.60 (Â£6) per 1000 advert views, with YouTube taking a percentage.
YouTube is changing the rules about when users can start earning money through carrying adverts on their video channels.