China has made sound progress in addressing the prominent problems over environmental protection along the Yangtze River Economic Belt, the country's Ecology and Environment Minister Li Ganjie said Monday.

After two years of work, 99.9 percent of the 1,474 drinking water sources in cities above the county-level along the Yangtze River Economic Belt, stringing up 11 provinces and municipalities from west to east, have had their problems resolved, Li told a news conference on the sidelines of the annual legislative session.

Meanwhile, over 90 percent of the 12 "black and malodorous water bodies" in the provincial capital cities have been cleaned up, while prefecture-level cities are catching up on this front, Li said.

A special campaign targeting illegal disposal of solid and hazardous waste along the Yangtze, China's longest river, has also been successful, the minister said, adding that the country has made notable progress in enhancing protection of the nature reserves in the Yangtze River basin.

The country will continue to improve the supervision system for Yangtze protection, Li said.

China has made the "defense of lucid waters" a primary task in the battle against pollution for 2019. Research will be conducted for the drafting of laws on bio-security and Yangtze River conservation this year, according to the work report of the Standing Committee of the 13th National People's Congress.