The trial in Stockholm will last until Friday. Two members of his team are also judged.
If found guilty, A $ AP Rocky faces up to two years in prison and a fine.
In pictures of the victim taken by investigators on June 30 and released last week by the Swedish press, deep wounds can be seen on various parts of the body.
One of the two complainants – there is only one in the criminal proceedings – also hit a member of the artist's team. A parallel investigation has been opened, but the prosecution has dropped the lawsuit, saying the rapper had only responded to the assault he was a victim of.
Several US congressmen urged Sweden to release the artist, and a former US ambassador to Stockholm, Mark Brzezinski, reported in mid-July that he contacted Sweden's Foreign Ministry and the Royal House to denounce "racial injustice." "
The rapper's lawyer from New York rejected this accusation, saying at a press conference that Sweden "is not a racist society."
Since his arrest, friends and fans of the artist have called for his release. More than 630,000 people signed an online petition and a social media campaign was launched to encourage fans of the artist to boycott Swedish brands like Ikea.
A $ AP Rocky's plight came to the White House, where Donald Trump said he was willing to present himself "in person" as collateral.
But unlike in the United States, Sweden does not have a bail release system and its justice allows a defendant to remain in provisional detention until his trial.
"Very disappointed by Prime Minister Stefan Lofven for being unable to act. Sweden has disappointed the African American Community," Trump criticized on Twitter, adding: "Give A $ AP Rocky your freedom."