Glickman's comments followed reports that China has told the US majors they cannot release their films in the territory. Eye witnesses said few if any cinemas in Shanghai were screening current Hollywood releases.
Last week Will Smith told reporters in Hong Kong that Warner Bros has been blocked from releasing the upcoming horror-sci-fi film I Am Legend.
'It is increasingly clear that China may have instituted a block on the import of American films into their country,' Glickman said. 'Although we have not received official confirmation of such a ban from the Chinese government or China Film, the indicators are strong that our information is correct.
'If such action has been taken, or is in the process of being taken, it would represent an enormous step backwards in terms of China's efforts to develop a strong and most importantly, legitimate film exhibition and distribution market.
'If these reports are true, it is unacceptable that China has taken this action and we will bring all our resources and leverage to bear to address this situation.'
China frequently limits the number of foreign releases during holiday seasons as officials strive to attain a 50% market share for local titles. Last year authorities pulled The Da Vinci Code out of cinemas three weeks into that film's sell-out run.