Defence counsel Anne Stevens QC said Xu was arranging to have his in-law's bodies sent home.
His case was heard in the Dunedin District Court because his wife, who was sitting in the front seat, was still receiving treatment at Dunedin Hospital.
Prosecutor Sergeant Chris George, reading from the summary of facts, said one of the passengers in the other car suffered extensive fractures and two others were also injured.
Xu, who had a calm demeanour in court, appeared with the assistance of an interpreter, and pleaded guilty to all of the charges - three counts of careless driving causing death and four of careless driving causing injury - he was facing.
Judge Turner convicted Xu on all seven charges and remanded him to appear in the Timaru District Court on June 20.
Stevens said Xu was "thought highly of by his colleagues" and was worried about losing his job when he returned to China if photographs of him appeared in the media.
A presentence report and reparation report was ordered, and restorative justice was to be explored.
A decision on whether media could film or take photographs of Zu was deferred.