At the opening, Shiner was bombarded with questions about the connections between Andy Warhol's Asia tour and Warhol's works' auction by Christie's at Shanghai three days before its show in Beijing. The exhibition toured Hong Kong last December and Shanghai in April.

The hammer price of Warhol's Diamond Dust Shoes was 4 million yuan ($657,200) at Christie's sale in Shanghai, but the touring exhibition was not connected to the auction sales, says Shiner.

"Our museum will never sell any of Warhol's works, " repeats Shiner.

Beuys, meanwhile, is much less known than Warhol and his exhibition Social Sculpture - Beuys in China was quieter.

The German performance artist is regarded as one of the most influential artists of the second half of the 20th century. Beuys' works are harder to understand than Warhol's, as he sought to overthrow the public's sense that art is a piece of painting.

There's no painting in Beuys' art, says Zhu Qingsheng, art professor with Peking University who has been researching Beuys for years. Many Chinese art professors think that performance art is being naked, but that's because they never really know Beuys, Zhu insists, quoting Beuys' "Everyone can be an artist".

Xu Juan, co-curator of the Beuys show, says even in his motherland Germany, Beuys is perceived as a socialist rather than an artist.

Michael Berger, a German collector of Beuys, says it took him 20 years to understand his art.

Even so, Wang Huangsheng, the director of the CAFA Art Museum and co-curator of the Beuys' exhibition, stresses the importance of the exhibition. Although many Chinese artists know the name of the German artist, the show is a chance to look deep into what is a real Beuys, adds Wang.

Every Chinese can see Warhol's works on advertising boards at bus stops, he says, but if they want to see Beuys, they have to go to the museum in person.