People are reflected in a mirror as they shop during Black Friday sales in New York November 29, 2013. Black Friday, the day following Thanksgiving Day holiday, has traditionally been the busiest shopping day in the United States. [Photo/Agencies]

WASHINGTON - Over 131 million people are expected to shop online on "Cyber Monday," the biggest sales day of the year for e-commerce, said the survey of the National Retail Federation (NRF) on Monday.

According to the survey, 43.3 percent of people will pounce on Cyber Monday deals as the first thing in the morning.

"Despite record-breaking online shopping Thanksgiving Day and Black Friday, holiday shoppers aren't done yet; we expect Cyber Monday to be bigger than ever," said NRF President and CEO Matthew Shay.

The survey showed that mobile device played a more and more important role in online shopping as consumers increasingly rely on their smartphones and tablets to reach and buy products.

The survey showed 24.8 million said they would use their mobile device, a 22 percent rise last year and a drastic change from the only 3.7 million in 2009.

Eight out 10 online retailers will offer specific Cyber Monday deals. More than half of retailers have their mobile websites and apps cleaned up in advance and their supply chain operations ready for record-breaking digital traffic, said the survey.

On the same day, NRF has published its prediction for the sales through the Thanksgiving weekend. The number is 57.4 billion U.S. dollars, slightly lower than the $59.1 billion reached in 2012.

The last time to record decline in Thanksgiving weekend was in 2008 just after the financial crisis broke out, according to the data of NRF.