The NSPCC's Childline service polled 700 children and said 12 per cent had admitted to making or taking part in sexually explicit videos.
It also revealed that one in ten 12 and 13 year olds were worried they are addicted to porn.
Childline said young people are turning to the internet to learn about sex and relationships. It has launched a new campaign FAPZ - the Fight Against Porn Zombies - that uses animation to look at the consequences of porn on girls and boys.
Vivienne Pattison is a Christian and the Director of Mediawatch, a group that campaigns against violent, sexually explicit and obscene material in the media. She said she was shocked the number was not higher and stressed that parents and children need open lines of communication to discuss pornography.
Speaking on Premier's News Hour, she said: "We've let a generation down here, we don't know what the affect is going to be on these children.
"In fact one of the children that was interviewed for this project by the NSPCC was 13 and he said 'I don't know how this is going to affect me when I grow up, I'd really like to get married and have a relationship but I don't know whether I'll be able to', which I thought was incredibly mature of a 13-year-old to think that.
"But he's quite right, we don't know 10, 20, 30 years down the line what exposure to this kind of material at such a level is going to have on the rising generation on their ability to form relationships and join in with society."
Listen to Vivienne Pattison speak to Premier's Antony Bushfield here:
Christian Charity CARE also commented. The CEO Nola Leah said: "These latest findings are hardly surprising given the failure of the Government to ensure all internet providers must include a robust system of age verification.
"If we really care about protecting children online then we must use the law to do so.
"Right now, children have access to sickening images and shocking content online and all can be accessed 24 hours a day at any given time and using a variety of platforms.
"Parliament must take action to make sure internet providers are required to do far more to protect people because while the online world has grown at a pace, legislators are still playing catch-up.
"The rising generation will suffer unless action is taken. We've seen small steps in the right direction but we cannot afford to sit back on this issue any longer, figures such as the ones released today demand a response."
