According to the survey conducted on 1,030 parents and 1,000 children by identity firm Garlik, as many as one in four 8-12 year olds have been ignoring the age restrictions of 13 or 14 on the use social networking sites, like Facebook, MySpace and Bebo.
The online identity experts found that nearly 20 pct of the respondents agreed on meeting strangers as friends on social networking sites.
The survey also showed that about 72 pct of the parents checked their child's web surfing habits.
About a quarter of parents surveyed agreed that they secretly logged into their child's networking page and checked if they are befriending strangers.
And some 89 pct of parents interviewed said that they spoke to their children about the dangers posed by social networking sites, and about 58pct said they were more vigilant online now than a year ago.
Tom Ilube, chief executive officer of Garlik, said "children are at the vanguard of the social networking phenomenon", using such sites such "in the same way other generations used the telephone".
"What you find with young people is that they tend to be a lot looser with their personal information than more canny older people," BBC quoted him, as saying.
"That can be OK if they are in a fairly tightly-controlled environment, but when they are in an environment where they're mixing with people much older than them, then that's something to be quite cautious about."
"Busy parents can't be expected to monitor their children's activities all the time. What are Facebook, Bebo, MySpace and the others doing to help?" he added.