Relatives of the victims gathered at the court as the sentences came in
Two men have been given the death penalty for their involvement in China's contaminated milk scandal.
The former boss of the Sanlu dairy at the centre of the scandal was given life imprisonment.
They were among several sentences handed down by the court in northern China, where Sanlu is based.
The scandal, in which melamine was added to raw milk to make it appear higher in protein, led to the deaths of six babies and made some 300,000 ill.
It led to product recalls across the globe, and further damaged China's reputation for producing safe and reliable products, the BBC's Quentin Sommerville in Beijing says.
At home, the scandal left parents terrified and caused outrage across the country, coming only four years after an earlier milk powder scandal which left 13 babies dead, he adds.
Victims' relatives protested outside the courthouse in Shijiazhuang on Thursday. Some said they had been prevented from attending the trial by authorities anxious to contain anger over the affair.
The most senior figure to be sentenced was Tian Wenhua, who was chairwoman of the Sanlu Group, the largest producer of baby milk powder.
10 Sept: 14 babies reported ill in Gansu province
15 Sept: Beijing confirms first deaths from the contamination
22 Sept: Toll of ill babies rises to tens of thousands - and eventually will rise to almost 300,000
23 Sept: Other countries start to test Chinese dairy products or remove them from shops
31 Oct: Chinese media suggest melamine is routinely added to animal feed
23 Dec: The main dairy firm involved, Sanlu, files for cy
31 Dec: Four senior Sanlu executives go on trial
2 Jan:Firms involved ask for forgiveness in a mass New Year text message
22 Jan: A court in China begins handing down sentences
When the scandal broke in September, it emerged that Sanlu had known it was selling toxic milk - and allowed around 900 tonnes of it to leave its dairies.
It was only when its New Zealand partner intervened that production stopped.
Tian Wenhua pleaded guilty to charges of producing and selling fake or substandard produce in December.
The Intermediate People's Court in Shijiazhuang gave her a life sentence and ordered her to pay a fine of 20m yuan ($2.9m).
Sanlu itself was fined 50m yuan ($7.3m), Xinhua news agency reports, even though the firm has filed for bankruptcy.
Earlier the court sentenced cattle farmer Zhang Yujun and milk trader Geng Jinping to death.
Zhang Yujun was accused of running an illegal workshop in Shandong province in eastern China, producing 600 tonnes of the fake protein powder - the largest source of melamine in the country.
Geng Jinping was convicted of producing and selling toxic products to dairy companies from his milk production base.
One other person received a suspended death sentence, two were jailed for life and six - including three former Sanlu executives - were jailed for between five and 15 years for their part in the scandal, Xinhua news agency reports.
All together, 22 companies sold contaminated milk, which had been supplied by a chain of melamine producers and middlemen.
Sanlu's Tian Wenhua pleaded guilty at an earlier hearing
The dealers added the industrial chemical to boost the apparent protein content of milk, which had often been watered down to make more money.
Major dairy companies bought the milk from such dealers, failing to test the milk for purity and nutritional value.
The result was widespread poisoning of babies, the group most vulnerable to tainted milk as it was their only food source.
Kidney damage was reported in hundreds of thousands of people. At least six babies were killed by it.
The government has scrambled to fight off allegations that it reacted slowly to the crisis, by pledging to improve food safety standards and promising to bring the culprits of the scandal to court.
But families of the victims say China's lack of openness, public accountability and official corruption mean they have little faith that similar poisonings will not happen again, our correspondent reports.