Liziane Gutierrez took advantage of the warm Memorial Day holiday weekend to do what so many other women in Miami do -- show off her ass.

The Brazilian model soaked up the sun and hit the water in Miami beach Sunday in a barely there white one-piece swimsuit. She also hopped on a jet ski ... but strictly for selfie purposes.

Liziane's booty might look familiar. As we reported ... she dropped $25,000 to go under the knife a few months back to get an ass like Kim K.

Money well spent?