Dressed in a crisp suit, Li Zhirui, sitting on the window seat of a Beijing bus, silently gazes at the European-style villas, luxury cars and illuminated shopping malls as they pass him by.

As soon as his stop arrives, he takes off his tie and walks to his rickety second hand motorbike parked nearby.

A young couple make their way home in Tangjialing. Many young urban couples live in the Beijing village.

He doesn't even have a license. But he is far away from the city, safe from the traffic police and his colleagues, who might judge his life outside of the office.

After a 15-minute ride, he finally squeezes his way into the reality of life: An 8-square-meter room that costs 500 yuan ($74) a month, or a fourth of his salary, where he sleeps away his nights.

It's just another day in Li's life.

The 27-year-old native of Northeast China's Heilongjiang province is trying to save every penny he can to buy an apartment in the national capital.

His determination to one day become a homeowner has become even stronger after his fiance, a fourth-year university student, dumped him last month when he refused to buy a second hand car and an engagement ring for her.

"She hated the fact that I used to bring my drinking water from home and only bought her a cup of coffee when we went out," he said.

"My monthly salary is only 2,000 yuan. So you calculate how many cups of coffee I can afford."

Li's story is similar to that of many low-income graduates who have moved into the fringes of China's wealthiest cities like Beijing and Shanghai to squeeze out a living.

They are China's "ant tribe", a term coined by the country's sociologists to describe the struggling young migrants, who, armed with their diplomas, scramble to big cities in hope of a better life only to find low-paying jobs and disastrous living conditions.

According to a survey in the Blue Book about the country's talents, which was released by the Social Sciences Academy Press on Wednesday, more than 1 million such "ants" live in the big cities of China.

The survey said more than 100,000 low-income college graduates live in Beijing, and such groups also exist in large scales in cities like Guangzhou, Xi'an, Chongqing, Taiyuan, Zhengzhou and Nanjing.

The number of college graduates, aged 22 to 29, has been growing since China greatly expanded its university enrollment system over the past decade.

According to statistics from the Ministry of Education, the number of college graduates has jumped from 1.07 million in 2000 to 6.11 million in 2009.

The shabby houses where the "ant tribe" lives usually have many tiny restaurants, Internet bars, hair salons and clinics in close proximity, the survey said.

The "ants" don't have a stable job and their average salary is below 2,000 yuan per month, it said.

Lian Si, a post-doctoral fellow at Peking University, who wrote a book about the "ant tribe", said: "They share every similarity with ants. They live in colonies in cramped areas; they're intelligent, hardworking, yet anonymous and underpaid."

The embarrassing living situation of the "ant tribe" has been a serious social issue and the government should develop "second- and third- tier cities" to attract more graduates from big cities, the Blue Book said.