The Gap map also did not reflect Chinese claims to territory in the northeastern Indian state of Arunachal Pradesh, which China refers to as "Southern Tibet", or show its claims in the South China Sea, which overlap with those of several other countries in the region.
The company said they would be undertaking "rigorous reviews" to ensure that it doesn't happen again.
One user on Weibo posted photos of a Gap t-shirt saying it was in a Canada Gap store and that the map design did not include Taiwan or islands Beijing claims as its own in the South China Sea.
In January, China forced US-based hotel chain Marriott International to shut down and "conduct a full content inspection" of its Chinese website and mobile app after a questionnaire that listed Taiwan and Tibet as individual countries led to complaints.More news: Maple Leafs name Kyle Dubas as team's new general manager
"Upon the realization that one of our T-shirts sold in some overseas markets mistakenly failed to reflect the correct map of China, we urgently launched an internal investigation across the group and have chose to immediately pull back this T-shirt from all the concerned global markets", the company said in a statement. It also apologised for "this unintentional mistake and is now conducting internal investigations to quickly rectify this mistake".
The name change came in the wake of letters sent by China's Civil Aviation Administration in late April, pressuring 36 American and global airlines to remove references to Taiwan, Hong Kong and Macau as countries on their websites and marketing materials.
The clothing brand, based in the US, is the most recent worldwide business to be in trouble with the government of China over that country's territorial issues.
Fashion brand Zara and Delta Air Lines drew Beijing's ire and apologized for listing Taiwan and/or Tibet as countries on drop-down menus on their websites.
The spokesman said the foreign ministry is watching the situation and has called on Air Canada to change the designation back to simply "Taiwan".