Flight delays from Chinese airports were reduced last year, despite an increase in flight numbers, data showed.

Data from air traffic management revealed that 77.9 percent of scheduled flights were on time last year, a 2-percentage-point improvement from 2010.

Flights between Beijing and Guangzhou were the worst in terms of punctuality, at 66 percent, followed by flights between Beijing and Shanghai at 73 percent, said an official with the Air Traffic Management Bureau under the Civil Aviation Administration of China (CAAC). The official declined to give his name.

Still, "significant improvements" have been made on the two routes, he said, as the proportion of punctual Beijing-Shanghai flights increased by 30 percentage points, and those on Beijing-Guangzhou routes by 11 percentage points, compared to 2010, he said.

Li Jun, deputy director of the CAAC, told a working conference earlier that airlines, airports and air traffic control authorities have boosted cooperation to reduce delays, and capacity at major airports, such as Beijing, Nanjing and Chongqing, were expanded last year.

Flight punctuality will be targeted to improve by 2 percentage points this year, and average flight delays should be reduced by at least 5 percent.

Analysts said the opening of Beijing-Shanghai high-speed rail link in June, which halved rail transport time to less than five hours, has pushed airlines to improve performances.

Despite the improvement, however, passengers said that they have not noted any changes for the better.

He Wei, a frequent flier from Beijing, said he did not notice any improvement, not even on the Beijing-Shanghai route with a 30-percentage point jump.

"Last year, several Shanghai to Beijing flights that I took were delayed for one to two hours," he said.

"The improvement of 2 percentage points or 30 percentage points may be more of a statistical significance and does not mean much to travelers," he said.

Still, civil aviation officials, experts and airlines argued that the improvement was hard-earned, given increasingly busy air traffic.

The country's air transport fleet increased by 150 planes last year. The Air Traffic Management Bureau recorded a growth of 7.6 percent in the number of flights it handled, which reached 6.07 million last year.

"Just like on the highway, more cars will cause traffic jams. More planes flying in the sky will also produce congestion and delays," said Li Xiaojin, professor at Civil Aviation University of China.

The authority needs to control the purchase of planes and refine air traffic management to allow more planes to pass through quickly, he added.