Bronny James Throws Sick Dunks In Hoops Sesh with Shareef O'Neal

Here's a preview of what the NBA All-Star game's gonna look like in a few years ... Bronny James throwing some ferocious dunks while messing around with Shareef O'Neal!

The whole thing went down at LeBron James' Brentwood mansion -- where Shaq's sons, Shareef and Shaqir, rolled over for a shootaround with Bronny and some other friends, including Syracuse recruit Dior Johnson (one of the best high school players in the country).

LeBron was so impressed he whipped out his phone and started shooting video ... and it's pretty great.

Shareef seems to be doing REALLY well after heart surgery earlier this year. He's expected to get back on the court for UCLA next season.

Of course, Bronny just transferred to Sierra Canyon High School in Los Angeles -- one of the top hoops programs in the nation -- where he'll be playing with Dwyane Wade's kids.