Copyright infringement is threatening the survival of the millennium-old ceramic industry in Jingdezhen of East China's Jiangxi Province - China's traditional "capital of ceramics."

Hong Kemin, president of the copyright court of the Jingdezhen Municipal Intermediate People's Court, cited the trademarks "Jingdezhen" and "Longzhuge" as examples - both of which suffer from illegal copying.

Among the more than 70 trademarks registered in Jingdezhen, the two have been recognized as "well-known trademarks of China" by the State Administration of Industry and Commerce.

"Ceramic designs from Jingdezhen have been constantly copied, and trademarks of local brands can be found on porcelains produced around the country," said Hong.

He added: "The two trademarks have been illegally copied by dozens of producers in the country, who trade at home and abroad.

"Even at markets in Jingdezhen we can often find porcelains with the two trademarks on, which have been actually made in other parts of China."

Besieged by false "Jingdezhen" and "Longzhuge" ceramics, copyright owners have witnessed a shrinking market.

In the past decade, their annual sales volume in total has reduced from 800,000 to about 100,000.

"Since 2002, my copyright court has heard more than 20 appeals concerning the tort of the two trademarks, which account only for a small part of infringements that have happened," said Hong.

Meanwhile, "ceramic designers in Jingdezhen have been frustrated because their designs are pirated sometimes within one week after they appear on the market," said Chen Aihua, a police officer from Jingdezhen.

Liu Yuanchang, who was given the title "Master Designer of China" by the Ministry of Culture, said his favourite design of a porcelain statue, called "Arahat Haha," (Haha Luohan) has been copied so widely since 1990s that the price of each statue fell from about 1,000 yuan (US$120) to 20 yuan (US$2.4).

Zhang Songmao, also a "Master Designer of China," designed a ceramic picture based on the Tang Dynasty (AD 618-907) poem "Moonlit River in Spring" (Chunjiang Huayue Ye).

The ceramic became a collectors' item and copies were sold for more than 100,000 yuan (US$12,000).

But when Zhang traveled to Beijing in 2001, he found pirated copies at galleries with a price of about 40,000 yuan (US$4,820).

"Producers in Jingdezhen have often been criticized for their lack of creations and for sticking to traditional designs. But how can they invest in new designs with so many pirated items around?" said He Xingwu, secretary general of the Jingdezhen Ceramic Society.

"To prevent rampant copyright infringement, it's not enough that the local designers, producers and police make collaborative actions. We need tougher laws and policing," he added.