China Unicom is joining cloud vendors like Amazon, IBM, and Alibaba with its own cloud computing service in China.

The Chinese telecom company just launched a “full-service” cloud called Wo-Cloud that will offer cloud hosting and storage (among other services), reports Web Host Industry Review. It’s based on OpenStack, open source software developed by Rackspace and NASA that enables large-scale cloud computing deployments without proprietary hardware.

China Unicom will support Wo-Cloud from its Hohhot and Langfang data centers, with further expansion expected as it increases its investment and ramps up operations. The company expects to service government and enterprise customers.

The telecom is joining the fray during a period of rapid expansion for the Chinese cloud market:

Also, Microsoft’s Windows Azure and Rackspace both offer cloud services in China through their Hong Kong data centers. Companies in mainland China might be concerned about the speed and reliability of Hong Kong-based servers, though.

With more than a billion people, China represents a major growth opportunity for foreign and domestic players alike. Expect to see more momentum on that front as cloud vendors compete for a sizable slice of the market.