With an increasing number of Chinese consumers taking to websites to buy products ranging from clothes to electronics and even furniture, the number of complaints about such purchases has also increased.

Complaints regarding poor online shopping experience and problematic goods showed a 357 percent rise year-on-year in 2014, the country's top industry and commerce authority said on Thursday.

The State Administration for Industry and Commerce said in Beijing that the e-commerce sector has seen the fastest growth in the number of complaints. The overall growth in the number of complaints received by the SAIC in 2014 is 14.34 percent, said Yu Fachang, a SAIC spokesman.

Industry and commerce authorities nationwide received more than 77,800 complaints regarding online shopping, involving a total of 31.65 million yuan ($5.1 million) in transactions. Nearly 30 percent of the complaints were about contract disputes. Complaints on after-sales services and quality of purchased goods accounted for 22.7 percent and 21.7 percent, respectively.

With e-commerce becoming a significant part of daily life, authorities in China have now stepped up their efforts to protect the rights of online shoppers. Earlier last year, China revised its consumer rights law to include a seven-day cooling-off period for returning goods for refunds after online transactions.

But such efforts have had a limited impact. Analysts said e-commerce's unique features make it difficult for the authorities to regulate the industry.

"Most online retailers are small and medium-sized companies or even individuals. Many of them don't even have business registration certificates," said Wang Xiaoxing, an e-commerce analyst at Analysts International, a Beijing-based Internet consultancy.

"This makes it difficult for regulators to track fake products and hold relevant suppliers responsible," Wang said.

The surge in complaints about online shopping comes amid the thriving e-commerce market. Transactions involving online shopping hit more than 2.8 trillion yuan in 2014, up 45 percent from a year earlier.