Rivers is was upset after the Oscar-winning actress slammed her show 'Fashion Police' in an interview conducted last week.
In a Twitter post, Rivers said that the 'Catching Fire' star fell on her way to collect her Oscar trophy because 'she tripped over her own arrogance', reported Ace Showbiz.
"It is funny how Jennifer Lawrence loved Fashion Police during awards season when we were complimenting her every single week... But now that she has a movie to promote, suddenly we're picking on all those poor, helpless actors," Rivers wrote.
The feud started following Lawrence's interview as she promoted her new movie.
"Shows like the 'Fashion Police' and things like that are just showing these generations of young people to judge people based on things that don't matter," the 23-year-old actress said.
"They put values in all the things that are wrong and show that it's ok to just point at people and call them ugly and call them fat and they call it fun," she added.