Terry Grimley struggles with work from China and California from the Frank Cohen Collection.

All roads seem to lead to China at the moment. In the course of two days recently I was hearing about it at three contrasting exhibition openings on a Wolverhampton industrial estate, at Compton Verney and on Birmingham's Ladypool Road.

The idea has been around for a while that China is an awakening giant in world art, as in so many other walks of life. In the last couple of years Sothebys and Christies have sold more than #100 million pounds worth of contemporary Asian – mainly Chinese – art and some of the most hyped artists are becoming extremely rich celebrities. The best known of them, Zhang Xiaogang, has eight paintings in the Saatchi collection.

Frank Cohen, the Manchester-based collector who has opened a showcase for his collection at Four Ashes, near Wolverhampton, has also been buying Chinese art in a big way.

Time Difference, the second selection from Cohen's collection made by curator David Thorp – himself a leading expert on new Chinese art – juxtaposes Chinese painting with recent sculpture from Los Angeles. The exhibition's title reflects the fact that these very different art centres are separated by the Pacific.

My first glimpse of contemporary Chinese painting came in a show at MAC a few years ago, and while I don't recall if any of the same artists were in that show the combination of figurative painting and heroic scale seems broadly familiar.

Until recently it would have been assumed that contemporary artists in China would naturally be in conflict, or at least tension, with their government. Now it seems there are plans for a state-funded network of new museums across the country to show off their work.

All the painters here show the self-confidence to work on a monumental scale, albeit sometimes with a calculated banality of subject matter, as in Liu Ye's huge International Blue or Feng Zhengjie's China 2005 No 73, a huge stylised portrait of a beautiful and evidently fashion-conscious young woman.

Zeng Fanzhi is represented by three large full-length portraits, including a self-portrait in which he shows himself, wearing a long leather coat and gazing out from a hilltop, shown from the kind of low angle used to bestow gravitas on generals or political leaders.

Xiao Bo's Moscow gives a broad painterly treatment to black-and-white newsreel footage of Chairman Mao meeting Krushchev, while in his Beauty's Gone Li Qing takes a scene from the television coverage of Princess Diana's funeral, painting it twice with minor differences.

In their painterly treatment of images taken from mass media these Chinese painters seem to be following in the footsteps of their Western counterparts at several decades remove.

While it's always exhilarating to see ambitious, large-scale painting, the problem comes with trying to understand what these artists are actually saying about their raw material. When it comes to critical or ironic social comment there may be more interesting Chinese artists – the photographer Wang Qingsong, for instance.

It seems the last time I looked, American sculpture was minimalist, rigorously geometric and culturally overbearing. The selection of recent work from Los Angeles is just about the opposite of that – kitsch, vulgar, gaudy and deliberately trivial and messy.

Banks Violette's Hate Them (Single Stage) is a black (burned-out?) stage-setting incorporating drum stands as well as polystyrene, polyurethane and epoxy, which seeks to abstract the dark side of heavy metal culture.

His use of wildly mixed materials is shared by several other artists including Terence Koh, whose Chinese background provides a link between the two halves of the show.

The largest of Koh's three pieces, for example, incorporates 88 glass boxes containing bronze excrement and three cast bronze gold-plated heads of the artist.

Evan Holloway's two pieces are equally eccentric in imagery and materials. I wondered if his Capital, which perplexing incorporates a large number of small nude female figures, could be making some kind of comment on pornography. It most probably isn't, though.

At least something to be said for this West Coast sculpture is that, unlike earlier American styles – or the new Chinese painting – it will not lend itself easily to the cause of cultural imperialism.

 Time Difference: New Art from the US and China is at Initial Access, Four Ashes, near Wolverhampton, until July 26 (Monday-Thursday 11am–4pm, Sat 10am-4pm; admission free). Units 19 & 20, Calibre Industrial Park, Laches Close, Off Enterprise Drive, Four Ashes, Wolverhampton. For further information call 01902 798999 or visit www.initialaccess.co.uk.