The service is code-named "Tahoe" and is designed to help the company boost its online business and take on other e-commerce giants like Amazon.com.
Wal-Mart, the world's largest retailer, told The Associated Press on Wednesday that the shipping subscription service will cost customers $50 a year.
Products will arrive in three days or less.
Ravi Jariwali, a Wal-Mart spokesman, says the service will be available by invitation only for now and it will offer more than one million top-selling items, from toys to electronic gadgets. Wal-Mart's online site sells more than seven million products.
The service is part of a software overhaul that will span several years. "Tahoe" was supposed to be launched last year before the holiday season, but the company now anticipates a launch in the early summer of this year, according to The Information's report.
—AP contributed to this report.