LeBron James couldn't help but think about his own boys after Trayvon Martin's death ... saying he realized that could've been one of his kids who was killed.
TMZ Sports has a first look of the final episode (airs Saturday at 9 PM) of his 3-part docu-series, "Shut Up and Dribble" ... which focuses on the impact NBA players have when it comes to social activism.
"I'm sitting there and I'm reading all these different articles," James says, "I'm seeing all these different play-by-play. I'm seeing all these different stuff of what happened, what didn't happen, what could have happened to prevent this ... and I just started to think about my boys, my sons."
LBJ has two sons -- Bronny (14) and Bryce (11) -- and one daughter, Zhuri (4) -- and has talked about the impact Martin's death has had on raising his kids.
The clip is pretty powerful ... with soundbites from President Barack Obama, Chris Bosh and Etan Thomas speaking about the tragedy.