"It manifests that young people with degrees have ample promotion opportunities, but on the other hand, we are lacking youth on the front line," Ji said.

Regional managers in charge of about 1,000 security guards can earn about 10,000 yuan per month in the company, he said.

Tang Peigan, deputy manager of Shanghai Qinghua Security Management's human resource department, said many university graduates just took the job as a transition.

"They can earn about 3,000 yuan a month, with board and lodging, and switch to other jobs as soon as they find them," he said.

Tang did not reveal how many security guards with degrees the company has, but said "there is only one such guy in 100 ordinary security guards".

The situation in State-owned security service companies is a bit better. Zhou Jianping, a representative of Shanghai Bailian Security Service, said they have about 15 security guards with degrees among their 2,000 employees.

"Their salary is about twice that of ordinary security guards, and normally they can be promoted to be a regional manager or to management level after one or two years," Zhou said.

Zhou expects more recruits from universities as it is becoming more difficult for them to find jobs - a record 6.99 million students graduated from Chinese universities this year.

Fang Fulai from Weldon Security Service said it is important for university graduates to give up their stereotypical view of the security service industry.

"By now, there is not a leading security service company in China that can rival foreign big companies such as the G4S Security firm that protected the 2012 London Olympics, so there is great potential in this industry," he said.

The company is intending to recruit some university students as interns.

In addition, Shanghai introduced five grades of qualification certificates for security workers in 2009. To win a top-rank certificate, one needs to have a bachelor's degree and several years of experience in the sector.

Statistics from the Shanghai Security Association showed that by the end of 2012, the city had 124 registered security companies, a sharp rise from 32 companies in 2009. The number of security guards reached nearly 130,000 and the industry's annual turnover had grown to 6.9 billion yuan.

There are about 3,000 registered companies in China's security service sector, employing more than 4.3 million security workers, according to a 2012 report by the China Security Association.

Jiang Yinan in Shanghai contributed to this story