Events are due to be held across South Africa to remember the 34 people killed during clashes at the north-eastern Marikana platinum mine last week.
Early in the morning, a traditional cleansing ceremony will take place at a stadium near the mine.
Later, officials and religious leaders will join miners for a memorial service at a nearby church.
The Lonmin-owned mine has been closed since workers went on strike to demand higher pay two weeks ago.
Among those attending the service at the Nkangeng Informal Settlement, near the mine, will be the head of President Jacob Zuma's office, Collins Chabane.
Visiting the mine on Wednesday, Mr Zuma told workers he "felt their pain" and promised a thorough investigation of the shootings.
But correspondents say the mood at the meeting was subdued, and did not feature the cheering and ululating that usually greets the president.
Some of those present chanted,"down with the police".
Religious leaders have brokered talks between the Lonmin management and workers in an attempt to break the deadlock in the dispute over pay.
On Tuesday, Lonmin dropped its threat to fire workers if they failed to end their strike after many workers ignored the ultimatum. The company says the strike is illegal.
Police said they opened fire last Thursday because strikers wielding machetes and clubs had refused to lay down their weapons.
Another 10 people, including two police officers, had died in clashes the previous week.
The striking miners say they are currently earning between 4,000 and 5,000 rand (£305-£382: $486-$608) a month and want their salary increased to 12,500 rand.
The company says most workers are paid about 10,500 rand, if bonuses are added.
Industrial conflict over pay appeared to be spreading to other mines in South Africa on Wednesday, with about 600 workers at the nearby Royal Bafokeng Platinum Mine also going on a strike to demand higher wages.