Fang Zhiqian loves the smell of firecrackers. The pungent, burning chemicals takes the 16-year-old back to scenarios of family which he often missed during his childhood.

Zhiqian was only three years and four months old, when his mother, Xie Kui'e left their home at a plain village in Luoshan County of central China's Henan Province to look for a job.

He was seven, when his father left him and his elder brother and went to join in their mother in eastern Zhejiang Province as a pedicab driver.Zhiqian became one of the "left-behind children" in China, whose one or both parents work far away from home, leaving them taken care of by their grandparents or other relatives.

"My parents aren't in my most pleasant memories," says Zhiqian. The quiet 12th-grader is reluctant to talk about his childhood, because he always felt lonely at that time.

As China sped its way from poverty to prosperity, the world's most-populated country has confronted an old problem --- the poor-rich disparity. China's vast rural population has begun to enjoy the country's development, though later than their urban peers, as more and more farmers have moved to cities to seek fortune.

However, it's a bittersweet process for most of the wage hunters. While they earn more than they did back home, they pay the price of a family integrality. Children, like Zhiqian, are the prime victims.

A report released by the All-China Women's Federation in May reveals that China now has more than 58 million rural, left-behind children. Almost triple the figure in 2006. And over 69 percent of them are under 14. These children are inferior to peers who enjoy full family care. The left-behind are also behind in physical and psychological health and learning, and more vulnerable in security.

"The issue of the left-behind children, which is the concern for millions of migrant workers and their families, is of great importance to China's social harmony and stability," says the report.

Fang's hometown Luoshan has a population of 730,000, about 90 percent of which live in rural areas. Since the mid 1980s, more than 220,000 people from Luoshan have moved to work in cities, mainly to Beijing and the eastern coastal provinces.

"They seek jobs in the construction and catering industry", says Xiong Xingming, head of the county's labor and social security bureau.

"Almost every family has at least one member working in the cities and the villages now are only home to the '38-61-99' troops." These three pairs of figures refer to the dates of Women's Day, Children's Day, and Elderly's Day in China.