The newspaper's editorial said: "We still have a long way to go in order to make substantial progress in narrowing the gap between rural and urban areas."
Five years ago, the government made improving rural income a pillar of its political programme, a policy that appears to have failed.
Farmers were reportedly prospering at a rate not seen since the mid-1980s, but the urban Chinese were getting richer at an even faster rate.
"It is a battle we cannot afford to lose," the China Daily warned.
"How this task is fulfilled is believed to bear an impact on the overall strength of the country."
In March, Wen Jiabao, the Chinese premier, identified income distribution as a priority area, saying his government would raise rural incomes "through a variety of channels".
"Agriculture ... remains weak, and it is now more difficult than ever to steadily increase grain production and keep rural incomes growing"
Wen Jiabao, Chinese premier
He said: "Agriculture, the base of the economy, remains weak, and it is now more difficult than ever to steadily increase grain production and keep rural incomes growing."
The widening wealth gap was also identified by Hu Jintao, the president, as a key problem in his long-term objective of building a "harmonious society".
On Friday, latest figures from the National Bureau of Statistics showed investment in factories, real estate and other urban assets increasing 26.7 per cent in the first eight months of the year.
This is despite curbs meant to prevent unchecked spending and to control soaring house prices, a development leaders worry could ignite a financial crisis.
The government is trying to check investment in real estate and industries including automobiles and textiles, but money pouring in from China's exports has made it difficult to contain.