SHANGHAI - A survey to judge the international image of Chinese cities was released in Shanghai on Monday, with the financial hub scoring the highest among all the 30 cities that were tested.

The survey, co-conducted by Gallup Consulting, a global consultancy, was launched in April via an online questionnaire circulated among foreigners living in the Chinese mainland and abroad.

A total of 7,980 foreigners took part in the survey.

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Every city needs to be judged by more than 200 foreigners on average to make the sample valid for scientific research, according to Wu Tao, chief consultant of Gallup Consulting China.

Thirty Chinese cities were rated in 12 criteria - attractiveness, culture, environment, citizen qualities, security, traffic, individuality, integrity, government efficiency, investment value, development potential and internationalization level.

Shanghai and Beijing came out with flying colors in terms of the general impression among foreigners. Chengdu ranked third on the list, with its citizen qualities scoring the highest among all 30 cities.

"People often refer to Paris as the home of fashion and Vienna as the home of music," said Wang Changyuan, deputy general secretary of China Association of Mayors. "Similarly, promoting a city's image will help make it much better known, hence attracting more talents and investments."

Meng Jian, director of the International Public Relations Research Center of Fudan University, which co-conducted the survey with Gallup, seconded Wang.

"While China has overtaken Japan to become the second-biggest economy in the world, it remains unknown how foreigners think of Chinese cities. The survey was conducted to give a comprehensive, scientific and objective evaluation of some cities," said Meng.

Shanghai ranked the top in most of the criteria, including integrity, government efficiency, investment value, development potential and internationalization level.

But when it came to social security, it sunk down to the 9th position, while Xi'an, capital of Northwest China's Shaanxi province, emerged at the top.

Wu Yuhong, professor of criminal law execution at the Shanghai University of Political Science and Law, said the reason for Shanghai falling behind in social security can be largely attributed to its high floating population.

"According to previous researches conducted by our department, the crime rate of a place is proportional to its floating population. As Shanghai is such an international cosmopolitan city, where hundreds come and go every day, the possibility of crime is much higher," said Wu.

"Shanghai's crime rate has been on the rise in recent years. Property crimes are the most prevalent," he said.

According to Wu, the root cause of the city's deteriorating social security net is the widening income gap between the rich and the poor.

"Those who come from the rural areas face razor-sharp competition as well as all kinds of temptations in Shanghai. If they can't handle the pressure they resort to illegal means.

"The incompleteness of a well-functional social security system can never be exempted from the reason of crime."