BEIJING, Jan. 7 (Xinhua) -- The air quality in 338 Chinese cities improved in 2018, the Ministry of Ecology and Environment said Monday.

A total of 338 cities enjoyed good air quality on 79.3 percent of days last year, up 1.3 percentage points year on year, meeting the air quality target for the year, according to the ministry.

In the Beijing-Tianjin-Hebei region, the share of days with good air quality stood at 50.5 percent, a year-on-year increase of 1.2 percentage points, while the PM 2.5 density of the region dropped by 11.8 percent year on year to 60 micrograms per cubic meter.

The Yangtze River Delta area saw the share of days with good air quality up by 2.5 percentage points to 74.1 percent while the PM 2.5 density dropped by 10.2 percent to 44 micrograms per cubic meter.

Harbin and Changchun in northeast China were among the cities that saw major air quality improvements last year.

China released a three-year action plan on air pollution control last year, vowing to cut emissions of sulfur dioxide and nitrogen oxide by more than 15 percent by 2020 compared with 2015 levels.

Meanwhile, cities at prefecture level and above should see their numbers of good air days reach 80 percent annually, and the percentage of heavily polluted days decrease by more than 25 percent from 2015 levels, according to the plan.