Online shopping drew the largest number of complaints in the e-commerce industry last year, according to a report released on Wednesday.

The China Electronic Commerce Research Center, an independent research institute based in Hangzhou, Zhejiang province, collected about 100,000 complaints related to e-commerce via its online platform.

It found that 52 percent of the complaints involved online shopping, far outstripping other activities such as group purchases.

Clothes, digital products and household appliances drew the most complaints, because the three categories were also the most popular products for online shoppers.

"It is not surprising that online shopping got so many complaints, because the business is developing too rapidly," said Qiu Baochang, director of the Consumer Rights Protection Committee of the Beijing Lawyers Association.

Consumers spent about 800 billion yuan ($126.3 billion) on online shopping in 2011, Commerce Minister Chen Deming said earlier.

The number of online consumers hit 194 million in 2011, according to the China Internet Network Information Center.

The CECRC study found that the biggest number of complaints came from the cities of Beijing and Shanghai and Zhejiang province.

Complaints tend to peak during holidays, when e-commerce sites are often busy. The volume of complaints partly reflects the large number of shoppers, as well as the nature of e-commerce, said Qiu.

Consumers can only see product images, and they don't meet the actual sellers, Qiu said. Therefore, it's difficult to ensure the consumers' right to know. "To protect consumer rights, legislation involving electronic commerce is necessary," Qiu said.

"Many of the complaints could have been avoided, if stricter regulations and supervision were established," said Yao Jianfang, senior researcher at CECRC.

Qiu said new regulations would be announced on International Consumers' Rights and Interests Day, which is Thursday.

A major complaint from buyers is that what they receive is not what they saw online, the report found.

Zhang Jing, a 32-year-old woman living in Beijing, bought a skirt online in July 2011, but she said the fabric was so thin, she didn't want to wear it outside the house.

"It is totally different from the picture," Zhang said. "The seller used a picture from a fashion magazine and the skirt is not the same one."

But she said she gave up complaining to the authorities because she was unable to prove her case after the seller deleted the online image.

"Another problem for those complaining about online shopping is the difficulty of collecting evidence," said Yao, since most of the "evidence" is electronic and fleeting.

Consumers should be aware of their legal rights and maintain evidence through screen captures, Yao suggested.

After-sales service is also a problem of e-commerce.

Up to 96 percent of respondents said the availability of refund and exchange services were key considerations, according to another survey, conducted by Guangzhou-based Modern International Marketing Research Ltd.

The survey interviewed some 4,500 regular online shoppers in major cities including Beijing, Shanghai and Guangzhou in February, and targeted the operators of 15 major electronic businesses.

According to the survey, more than 60 percent of the respondents won't shop at a website that doesn't offer satisfactory refund and exchange services.

"Unlike malls, websites cannot give customers the chance to try goods before buying," said Liu Xuemei, a regular online shopper in Guangzhou. "E-commerce operators that provide sound return and exchange services will be respected by online shoppers," she said.

Contact the writers at wangwen@chinadaily.com.cn and jinzhu@chinadaily.com.cn

Qiu Quanlin contributed to this story.