As with all other countries, China has recently seen a rise in 'predatory' open access journals. These publications sole purpose is to generate revenue from author fees, rather than promote scholarship. You can find much more information about predatory open access journals on the Publishing in the Sciences research guide (on the Choosing a Journal tab) and the Open Access research guide (on the Finding a Reputable Journal tab).
Here are a few warning signs that indicate a journal is predatory:
SciencePaper Online is an open access preprint server that covers 43 different STEM fields. Preprints are traditionally defined as manuscripts that have been accepted for publication but haven't been published yet. But some of the preprints in this server haven't been accepted for publication.
Below is a list of various institutional and governmental repositories that are open access:
Knowledge Repository of the National Science Library (part of the Chinese Academy of Sciences)