NANCHANG - A Dutchman who visited East China's Jiangxi province last week in the hope of finding the natural parents of his adopted Chinese daughter has told how the trip was satisfying though ultimately unsuccessful.

Jan Steenbergen, 45, said that he wanted to help his daughter -- Jiang Yongquan, nicknamed Quanquan -- find her birth parents as a Father's Day gift.

Though empty-handed on Tuesday, the night before his return to the Netherlands after two weeks' searching, Steenbergen said that he would feel better when facing Quanquan since he has done his best for her.

Quanquan, nine, was born in Yongxiu county in Jiangxi, and was adopted by Steenbergen in 2004 at the age of one.

In Yongxiu, Steenbergen put up many posters on kiosks, visited local orphanages, public security bureaus and hospitals, and even made key rings featuring photos of the girl and delivered them to residents living near the site where she was abandoned.

This was not the first time the hunt has brought him to Yongxiu.

In 2010, when Quanquan came up with the idea of finding her mum and dad, Steenbergen immediately agreed and spent several weeks in China.

A father of five daughters including two adopted Chinese girls, Steenbergen said he liked having a big family.

He adopted the other Chinese -- six-year-old Wei Kangying, who is handicapped -- in 2007 in Tianjin municipality, and has also visited Tianjin to look for Wei's birth parents.

Before adopting Quanquan, he and his wife spent six years going through adoption application procedures, including child rearing training and assessment of their financial stability.

In order to make their Chinese daughters feel at home, the couple decorated their home in a Chinese style.

Every year on Quanquan's birthday, Steenbergen would tell her that her natural parents took her to a warehouse along with a note of her birth date, reassuring her this means they loved her very much.

Quanquan is now in her third grade in primary school in the Netherlands. She ranked top of her class in academic performance and has shown gymnastic talent, according to her adopted father.

She is very happy and healthy now, but her well-being will improve further if she can find her natural parents, said Steenbergen, a laboratory technician and regular volunteer who accumulated annual leave over several years to allow him to take time off to travel to China.