The number of vaccines in reserve will later surge to 100 million, but not before year's end, health ministry spokesman Deng Haihua told reporters.
"The number is expected to increase to 100 million when the country finishes its second phase of production," Deng said Wednesday, in comments posted on the ministry's website.
China kicked off its mass vaccination for the A(H1N1) influenza virus on Monday in Beijing, apparently becoming the first nation in the world to start inoculating its population against the virus.
The Asian giant has been at the forefront of international efforts to produce an A(H1N1) influenza vaccine, with several domestic companies already obtaining government approval for production.
Officials however have warned demand will exceed supply.
The health ministry warned earlier this month that "tens of millions" of people could contract the virus in China in the coming months.
China had confirmed 14,581 cases of the virus nationwide as of Wednesday, according to health ministry figures, but no deaths have yet been reported by the government.
Of the roughly 39,000 Beijing residents inoculated as of Tuesday afternoon, 14 had reported adverse reactions, Xinhua news agency reported.
It quoted officials saying the reactions "may be" related to the vaccines and that authorities were investigating.
Authorities kicked off the vaccination programme by giving shots to students due to take part in mass celebrations for China's National Day on October 1.