Beijing's air quality is now at its best level in a decade, the city's top official said Friday.

During the first half of the year, Beijing had 23 more "blue sky" days than for the corresponding period last year, said Liu Qi, a member of the Political Bureau of the Communist Party of China Central Committee and Beijing's Party chief.

On 80.7 percent of the days in the first half of this year, air quality of Beijing was above level II, he said.

Beijing uses a five-grade classification of air quality on the basis of pollution indices, with Grade I being the best and Grade V the worst. Days with Grade I and II air quality are regarded as "blue sky" days.

Liu made the remarks at an Olympic Games' city forum organized by the Beijing municipal government a year after the games' opening ceremonies.

In 2008, Beijing had 274 "blue-sky" days, the result of vehicle restrictions for the Olympic Games and a 15-billion-U.S-dollar investment in air quality.

(Xinhua News Agency August 7, 2009)