Childline was contacted just under 800 times on Christmas Day, a 37% decrease on last year's total.
The service, which is open all year round for 24 hours a day, received 793 calls, texts and online contacts yesterday.
Last Christmas Day the total number of contacts was 1,267.
ISPCC Chief Executive John Church said more children are making contact online and by text rather than phone.
He says there is generally an increase on Christmas Day and Stephens Day in calls related to domestic abuse, but many of the contacts are from children who are lonely.
"Certainly around the Christmas period, we would see an increase in children witnessing domestic violence or difficult angry situations in the household and maybe being subject to violence as well," Mr Church said.
"So there would be a slight increase on Christmas Day and Stephens Day for those issues, but by and large we are seeing a trend over the years of family situation and loneliness creeping in as well.
"It’s really sad where young people would ring just to say they are lonely even though they may be in a busy household with siblings and parents. They still find themselves lonely and having to reach out to Childline."
Childline is available at 1800 666 666, or by texting to 50101.