Thailand signed a memorandum of understanding (MoU) with China, during the visit of Chinese Premier Li Keqiang last week, to sell 1 million tonnes of rice to Beijing per year.
Ms Yingluck said details of the government-to-government agreement would be worked out by a panel responsible for releasing rice stocks under the administration's rice-pledging scheme.
Commerce Ministry officials will later meet their Chinese counterparts to discuss further details of the rice sale MoU, the prime minister said.
"Basically, China has agreed to buy 1 million tonnes of rice a year from Thailand. The Commerce Ministry will elaborate on the details," she said.
Commerce Minister Niwatthamrong Bunsongphaisan, who attended the negotiations between Ms Yingluck and Mr Li, said the rice sale deal had nothing to do with a separate private sector rice sale agreement.
Thailand's Rice Exporters Association has secured a deal with Chinese shipping and transport giant Cosco Group in which Cosco has agreed to buy 1 million tonnes of rice from the association over five years.
Mr Niwatthamrong dismissed reports which quoted Cosco as saying it was not aware of the new rice trade deal between the Thai and Chinese governments.
He said the representatives of Cosco who visited Thailand along with the Chinese premier did not participate in the talks between the national leaders.
"I've already confirmed with the Chinese commerce minister the amount of rice in the deal which we plan to conclude by next month," Mr Niwatthamrong said.
He said China also wanted to buy other farm products such as rubber, tapioca flour and sugar from Thailand.
He added that the price of the rice to be sold to the Chinese government would be based on Thai and world market prices.
Thailand should be able to deliver the first shipment of rice under the deal to China early next year, he said.
Mr Niwatthamrong confirmed the government's plan to barter Thai agricultural products with Chinese high-speed trains. Thailand signed the MoU with China on the understanding Bangkok would order high-speed trains from China while Beijing would buy a substantial volume of agricultural products from Thailand in return, he said.
Ms Yingluck on Tuesday told the cabinet other agricultural products could be included in the barter agreement, in addition to rice, government spokesman Teerat Ratanasevi said.
The prime minister also mentioned that the government had expressed an interest in buying electricity from China as well, Mr Teerat said.