The party went down at the Hidden Hills home of Kim and Kanye, and gotta say ... it was pretty spectacular. The main party area was kinda dream-like ... with fluffy clouds scattered about.

Kim and Kanye had a bunch of snow hauled in, so the kids could sled down a slope.

The guest list was impressive -- J Lo, Alex Rodriguez, Sia, Paris Hilton, Dave Chappelle, Kimora Lee Simmons and Tyler, the Creator.

And, get this ... the singer -- John Legend, who performed a bunch of songs off his Xmas album, "A Legendary Christmas."

Check out North planted on Kanye's shoulders as he dances to his buddy, John.

The Kardashians Xmas card this year is predominantly girls. It's pretty fitting that the matriarch of the predominantly female family was given a baller gift ... for Christmas, Kris got a custom-made Goyard suitcase, which runs upwards of $15k.

Just another fashionable reminder that they're rich as f***.