One Chinese writer is quoted as saying she was “scared to death” on seeing the image of the creature with its claws, scales and bared teeth.
China Post, which produced the stamp, insists it is a perfect combination of history and modernity.
The stamp’s designer says a tough image was needed for a powerful creature.
“Among everyday people, the dragon is thought to exorcise evil spirits, avert disasters and give blessings, so we need a tough image,” Chen Shaohua is quoted by the China Daily as saying.
The dragon has been a symbol of Chinese imperial power for centuries.
But media figures and people posting on Chinese microblogging sites have said the image is inappropriate and too ferocious.
Among the critics of the stamp is Xu Lin, a senior editor at the official People’s Daily, and an executive of the Photojournalist Society of China.
“It is justified to be unyieldingly ferocious if it is facing the outside”, said Mr Xu on his Sina Weibo page, “but this stamp is supposed to be used within the country most of the time.”
Mr Xu asked: “Is it suitable to be ferocious internally?”