A 24-year-old man has been sentenced to life in jail for killing a Sudanese refugee by running him down with his car.

Luke David Taylor, from the outer Perth suburb of Quinns Rock, had earlier pleaded guilty to hitting 29-year-old William Maker while he was waiting at a bus stop in the northern Perth suburb of Merriwa in April last year.

The Supreme Court earlier heard Maker was standing on the road trying to get Taylor, who was unlicensed at the time, to slow down.

Taylor was speeding, repeatedly going around a roundabout, spinning the car's wheels and revving its engine, the court was told.

He made no attempt to slow down, swerve or brake before he hit Mr Maker, and the driver did not stop following the incident, the court heard.

Mr Maker was under the influence of alcohol at the time of the crash, and the court heard this may have affected his decision to stand on the road.

Taylor's lawyer had earlier argued for a fixed prison term of at least 10 years rather than a life sentence, describing the case as "highly unusual".

Today's decision will see Taylor serve a minimum of 12 years in jail before being eligible for parole, backdated to April last year.

Supreme Court Judge Lindy Jenkins also disqualified Taylor's driving licence for seven years.

"Given the unusual circumstances, it would be clearly unjust not to impose a life sentence," she said.

William's sister Mary Maker said she was pleased with the sentence. ( ABC News: Emily Piesse )

Mr Maker's sister, Mary Maker, said outside court that while she was happy justice had been done, it would not bring William back.

"People expect me to jump up and be happy that he's been sentenced to life, but it doesn't change the fact that William is gone, he's never going to come back," she said.

"Luke is going to be in prison for that long time. There are still a lot of people out there doing the same mistakes, it is for the community to understand that life is important."

Ms Maker said the family was concerned over whether Mr Maker's wife, Susan, would be allowed to stay in Australia, as she arrived just days after he was killed.