City officials said in a notice dated late Wednesday that they were probing whether the gaffe in Marriott International's Mandarin-language questionnaire violated national cyber-security and advertising laws.
Marriott has issued an apology and amended the online questionnaire, which asked members of the chain's customer rewards programme to list their country of residence, giving Tibet, Hong Kong, Macau, and Taiwan as possible options.
China claims indisputable sovereignty over all four of the territories and bristles at any suggestion of independence.
Thousands of outraged comments and reposts ensued, many urging a Marriott boycott.
Also Read
"Boycott Marriott! Get out of China!" one Weibo user said.
Another said that while Taiwan, Macau, and Hong Kong are sometimes listed separately, "it is the first time to list Tibet as such. This is too much".
Tibet is officially an "autonomous region" but firmly under Chinese control. Hong Kong and Macau became British and Portuguese territories, respectively, in the age of European colonialism but are now "special administrative regions" under China.
Shanghai authorities said they met with Marriott's management earlier this week to demand that the offending materials be corrected and that the company do its best to rectify the "bad influence" from the affair.
Marriott has said it was "deeply sorry" and wished to "reiterate our usual stand in respecting China's sovereignty and territorial integrity".
Marriott said it had fixed the errors and would "actively cooperate" with the government investigation.
China has meted out punishment for similar cases before.
Authorities did not specify what was wrong with the map.
Disclaimer: No Business Standard Journalist was involved in creation of this content