BEIJING - A coastal city in South China's Guangdong province has won the exclusive right to call itself "the city of happiness" in its tourism promotions in the country during the next 10 years.

That title was conferred on it by the State Administration for Industry and Commerce's trademark office.

"This also means other cities will not be able to brand themselves in such a way from now on," Zhang Meisheng, Party chief of the Zhuhai culture, sports and tourism bureau, told China Daily on Thursday.

Zhuhai was deemed one of the 10 happiest cities in China in 2007 on the basis of a two-month survey that asked residents of various Chinese cities to grade the places where they lived. Seeing its high ranking, officials in Zhuhai's tourism department hit on the notion of registering a trademark that associates the city with "happiness".

Official statistics show that the city welcomed more than 23 million tourists in 2010. Among the scenic attractions it can boast are a "lovers' road" by the sea, an imperial hot spring resort, and the New Yuanmingyuan Palace, which reproduces the landscape of the Old Summer Palace in Beijing.

Zhuhai, which borders Macao, was one of three cities in Guangdong province that were designated as special economic zones following the country's reform and opening-up in the late 1970s. The other two were Shenzhen and Shantou.

Although Zhuhai has obtained the right to call itself "the city of happiness", tourism experts said they question the wisdom of using a registered trademark to advertise a city.

"A city should think about what it can achieve rather than imposing restrictions on how others can use a particular label", said Zhang Guangrui, director of the Chinese Academy of Social Sciences' tourism research center.

"If we look at the average income of Zhuhai residents in the first half of this year, we could find it was just 18,000 yuan ($2,795)," said Feng Yonglue, a famous Chinese blogger, in an Internet post. "But the average price for one square meter of a residential house has increased beyond 10,000 yuan.

"When you see such a huge difference between incomes and property prices, can you really think city residents are that happy?"

Prior to Zhuhai, the trademark office granted tourism officials in Dalian, a port city in Northeast China's Liaoning province, the exclusive right to call Dalian "the romantic city".