"Merry Christmas from the Travolta family!" the Grease and Pulp Fiction actor captioned Friday's brief home movie, which shows a festively decorated tree and his kids -- surrounded by presents -- smiling, waving and saying, "Merry Christmas!"
Ella, 20, is wearing pajamas and holding a phone and Ben, 10, is shirtless in shorts and eating chocolate.
The family lives in Florida.
The video already has gotten more than 1 million views.
Preston -- whose credits included What a Girl Wants and Jerry Maguire -- secretly battled cancer for two years. She was 57 when she died.