The former Manchester United star was criticised by some fans after posting a photo with him and five-year-old daughter Harper on Instagram.
Speaking during a Facebook Live interview, he said: "We want to show our kids love."
David Beckham's wife Victoria was also criticised for posting a picture of herself kissing their daughter on the lips last year.
"I got criticised for kissing my daughter on the lips the other day," he said.
"I kiss all my kids on the lips.
"Brooklyn, maybe not. Brooklyn's 18, he might find that a little bit strange.
"But I'm very affectionate with the kids. It's how I was brought up and Victoria, and it's how we are with our children.
"We want to show our kids love and we protect them, look after them, and support them, and you know, we're very affectionate with them."
US actress Hilary Duff also received abuse last year after being photographed kissing her son at Disneyland in California.
There were dozens of comments criticising her underneath the photo, but in a response on Instagram Hilary defended her right to kiss her own son.
Another Hollywood actress, Jessica Alba, triggered a debate in 2014 when she was asked about the subject.
In a magazine interview, she said she couldn't believe that people were offended by kissing their own child on the lips.
David Beckham said he was proud of Brooklyn's photography career after recent criticism of his work by some art critics.
During the interview, he said Romeo, 14, loves tennis and that Cruz, 12, likes singing and playing the guitar.
He said Harper recently came up to him and said: "Daddy I would like to maybe play football."
"I was like, 'Oh my goodness that's amazing.'"