CHENGDU, May 8 (Xinhua) -- The first year in high school has been tough for Xiao Wei (a pseudonym): harder school work and stricter teachers. Fortunately, he has someone to talk to.

The boy from Ya'an City, southwest China's Sichuan Province, has regularly written to Chen Xing, a junior at Sichuan University, for two years under a pen pal program that was launched after a magnitude 8 earthquake devastated parts of the province in May 2008.

"At the beginning, 468 students from the Sichuan University volunteered to be pen pals of 610 students from nine primary and middle schools in the worst-hit areas, such as Beichuan County, to help relieve their trauma," said Professor Xiao Xu who initiated the campaign. "In line with the calculation method of the World Health Organization, millions of people could suffer from post-traumatic stress disorder caused by the quake, including hundreds of thousands of students."

"For a long time, sorrow and depression were anywhere in the campus. Children were silent and sensitive, and teachers had no idea what to do," said Guo Xiujuan, a teacher with Beichuan Middle School. "The letters from big brothers and sisters made them smile."

The program, "Colorful Stones," was named after a Chinese myth in which a goddess mends a broken heaven with colorful stones.

"We hoped to repair children's broken hearts, just like the goddess," Xiao said.

Even if pain inflicted by the disaster has long faded, the program has remained and expanded. Currently, more than 20,000 volunteers from several universities write to children in the province and neighboring Yunnan, Guizhou and Chongqing, offering psychological support and academic help.

"I still remember the first letter he [Xiao Wei] wrote to me. I read loneliness of a boy raised by his grandfather and lacking care from his parents," Chen said.

Encouraging Xiao Wei to work harder at school, Chen also reflects on herself: "I often tell myself to be more proactive and positive. So I would say he and I are growing up together."

The campaign epitomizes the bourgeoning volunteerism following the catastrophe. Official data showed that more than 1.18 million people applied to help with quake relief. The volunteers trooped into quake-hit areas on foot, bicycle and in their cars, giving anything they could toward those left homeless and grieving by the earthquake.

"The disaster prompted Chinese to unleash great power in volunteerism," said Wang Zhihao, an official with the Sichuan Committee of the Communist Youth League of China. "Thereafter, China had a new type of volunteers called emergency volunteers."

Right after the quake, Sichuan set up a team of certificated volunteers to respond to natural disasters. Now, the team has more than 5,000 members and consists of 10 contingents dedicated to respective fields, such as rescue, healthcare and psychological support.

"Over the past decade, volunteers and social organizations have thrived in Sichuan and become more professional facing disasters," Wang said.

Had not been a volunteer in Dujiangyan, one of the worst-hit areas, Li Jiahui, a graduate of civic engineering from Southwest Jiaotong University, would have been a building designer.

"It was my first time to work as a volunteer, and also the most unforgettable experience," said Li, an executive with a Sichuan-based poverty alleviation foundation. "We transported water and food, set up tents, and cleaned up…I just couldn't stop doing things, or I would feel really bad."

Back from the quake-hit region, Li rejected the design offer and started a one-year training for volunteers in Beijing, before obtaining a master degree in public relations in Singapore.

"The government has encouraged development of social organizations," Li said, adding that he believes the country will have more social workers.

The experience of being helped after the quake has also shaped the life of Du Cancan, then a student at Beichuan Middle School.

"[After the quake] My classmates and I were sent to a shelter …Volunteers were comforting us, holding our hands," Du said. "I never knew their names. But I remember the warmth."

Since then, she has been passionate about public welfare. After graduating from college in 2009, she co-founded a non-profit organization dedicated to assisting families in need and offering cultural services in communities in Chengdu.

The organization "I You She", with 212 full-time workers, has served more than 1,000 neighborhoods.

"Because of the disaster, I found the direction in my life," Du said.