Starbucks is opening one store in China every 15 hours, the company's China CEO, Belinda Wong, told "Squawk Box." China has become Starbucks' second largest and fastest growing market, and one the company expects to eclipse the U.S. market one day. Starbucks already operates more than 3,000 stores in the country and 2,000 more by 2021. The company on Tuesday company opened a 30,000-square-foot Reserve Roastery in Shanghai, its flashiest commitment to its growing Chinese business. It's the second Starbucks' Roastery to open and is twice the size of its flagship location in Seattle.

Exterior view of the new Starbucks Reserve Roastery in Shanghai, China. Justin Solomon | CNBC

"To us, we open 500-plus stores a year, but to us, it's not about 500. It's about opening a store 500 different times because you're in a different neighborhood and we've got to build that relationship with our customer," Wong said.

Starbucks CEO Kevin Johnson (l), Belinda Wong, CEO of Starbucks China (c), and Howard Schultz, Chairman of Starbucks. Justin Solomon | CNBC

Starbucks is now building more net new company-operated stores in China than in the U.S., said CEO Kevin Johnson, who replaced CEO Howard Schultz in April when the longtime leader transitioned into the role of executive chairman. In China, Starbucks' young baristas and shift supervisors receive a housing allowance subsidy, Wong said. The idea is to give those employees who have likely just finished college financial security.

Baristas working at the new Starbucks Reserve Roastery in Shanghai, China. Justin Solomon | CNBC