Griffin burst onto the NBA scene by averaging 22.5 points, 12.1 rebounds and 3.8 assists per game over 82 contests for the Clippers, who again missed the playoffs.
His unanimous selection was the first for an NBA rookie since San Antonio's David Robinson in 1989-90.
Griffin was the top pick in the 2009 NBA draft but sat out what would have been his rookie season with a knee injury.
He began this year with a double-double in his first game and went on to dazzle the league with his acrobatic displays and thundering slam-dunks.
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