Choi crashed his Chevrolet Cruze into a barrier while competing in the CTM Macau Touring Car Cup at the demanding street circuit.
He was cut free from the wreckage but later died in hospital.
Portuguese motorbike rider Luis Carreira (pictured) was killed in an accident on Thursday.
Carreira, an experienced Isle of Man TT rider, came off his Suzuki at a sharp corner and his bike burst into flames.
He was rushed to hospital where he was pronounced dead 20 minutes after arrival.
Meanwhile, Italian rider Stefano Bonetti remains in hospital after suffering multiple fractures in another crash.
"I don't think there is any question about the track, it has existed as it is for 60 years," said Joao Manuel Costa Antunes, co-ordinator of the Macau Grand Prix committee, who added that none of the weekend's remaining events would be cancelled.
Macau's 3.8 mile street track features extremely long straights, tight bends and narrow roads.
Although before this week, only one competitor had died since 1994 when French motorbike rider Bruno Bonhuil was killed in 2005.