The customs figures for rice exports were incomplete, but those available showed a sharp year-on-year increase from 3.5 million tonnes in the second quarter of 2016 to over 11 million tonnes in the second quarter of this year.
Although the international community recently agreed to punish North Korea over its nuclear programme, food exports were excluded from the UN sanctions in the hope of ensuring a minimum living standard for the country's citizens.
However, China banned North Korean seafood imports on Monday - cutting off a revenue stream that generated US$190 million for Pyongyang in 2016.
The increase in exports coincides with a food production shortage in the hermit state due to natural disasters like floods.
North Korea's food production - including staples such as cereals, soybeans and potatoes - in 2016 was estimated at 5.4 million tonnes, a fall of 9 per cent from 5.9 million tonnes in 2014, according to the Rome-based Food and Agriculture Organisation.
North Korea has had an ongoing food crisis since a serious famine back in the 1990s. Two in five citizens are undernourished and more than 70 per cent of the population relies on food aid, according to United Nations.
A UN report in March said, an estimated 18 million people across North Korea continue to suffer from food insecurity and malnutrition, as well as a lack of basic services.
Experts said the increased Chinese food exports might be a sign that North Korea's economy is slowly developing, but it still needed to rely on its neighbour for food as the international community has adopted a hard stance against Pyongyang.
"The surge can be a result from a bigger market demand from North Korea, since its economy is gradually reviving and the black market is booming, " said Cai Jian, a Sino-North Korean expert from Fudan University in Shanghai.
"It also showed the increasing dependence of Pyongyang on Beijing, since it cannot import anything freely from other countries," Cai added.
But Justin Hastings, an international relations scholar at the University of Sydney who has researched Chinese-North Korean trade, said the increased food trade between North Korea and China did not necessarily mean that people's lives had improved.
"The different types of food are going to the military and the elites in Pyongyang ... but people in the hinterlands are still going hungry. A wide variety of food being imported is thus not a sign that there is no food crisis," he said.