This study examines the representation of cultures across three sets of national English textbooks currently used in China by conducting a synchronic content analysis to explore what and how cultures are represented in the textbooks. Data analysis was conducted based on a newly constructed framework focusing on the content (countries and categories) and forms of cultural representation. Our findings mainly indicated that American and British culture dominated in the culture of inner circle countries and international culture was represented the least in all three textbooks, while Chinese culture was represented more than the cultures of inner circle countries in two sets of textbooks. As for cultural categories, the representation of cultural products was the most, and cultural perspectives and cultural communities were represented the least in all three sets of textbooks. Regarding the form of cultural representation, the cultural representation in implicit forms was, to varying degrees, more than that in explicit forms. Based on the findings, suggestions for English as a foreign language (EFL) textbook writers, EFL teachers and textbook researchers are provided.